EPA Document #: 815-R-05-005
(Minor Corrections, August 2009)
METHOD 527 DETERMINATION OF SELECTED PESTICIDES AND FLAME
RETARDANTS IN DRINKING WATER BY SOLID PHASE
EXTRACTION AND CAPILLARY COLUMN GAS
CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS)
Revision 1.0
April 2005
Ed K. Price, Brahm Prakash, Mark M. Domino, and Barry V. Pepich (Shaw Environmental, Inc.)
David J. Munch (U.S. EPA, Office of Ground Water and Drinking Water)
TECHNICAL SUPPORT CENTER
OFFICE OF GROUND WATER AND DRINKING WATER
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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METHOD 527.0
DETERMINATION OF SELECTED PESTICIDES AND FLAME RETARDANTS IN
DRINKING WATER BY SOLID PHASE EXTRACTION AND CAPILLARY COLUMN GAS
CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS)
1. SCOPE AND APPLICATION
1.1 This is a gas chromatography/mass spectrometry (GC/MS) method for the determination of
selected semivolatile organic compounds in drinking water. Accuracy and precision data have
been generated in reagent water, finished ground and finished surface water for the
compounds listed in the table below. The single laboratory Lowest Concentration Minimum
Reporting Level (LCMRL) has also been determined in reagent water.1
Chemical Abstract Services
Registry Number (CASRN)
Analyte
Atrazine 1912-24-9
Bifenthrin 82657-04-3
Bromacil 314-40-9
Chlorpyrifos 2921-88-2
Dimethoate 60-51-5
Esbiol 28434-00-6
Esfenvalerate* 66230-04-4
Fenvalerate* 51630-58-1
Hexabromobiphenyl 59080-40-9
2,2',4,4',5,5'-Hexabromodiphenyl ether (BDE-153) 68631-49-2
Hexazinone 51235-04-2
Kepone* 143-50-0
Malathion 121-75-5
Mirex 2385-85-5
Norflurazon* 27314-13-2
Nitrofen* 1836-75-5
Oxychlordane 27304-13-8
Parathion* 56-38-2
2,2',4,4',5-Pentabromodiphenyl ether (BDE-99) 60348-60-9
2,2',4,4',6-Pentabromodiphenyl ether (BDE-100) 189084-64-8
Prometryn 7287-19-6
Propazine 139-40-2
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Chemical Abstract Services
Analyte Registry Number (CASRN)
Terbufos-sulfone 56070-16-7
2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) 5436-43-1
Thiobencarb 28249-77-6
Vinclozolin 50471-44-8
* These are potential problem compounds (Sect. 13.2).
1.2 The Minimum Reporting Level (MRL) is the lowest analyte concentration that meets Data
Quality Objectives (DQOs) that are developed based on the intended use of this method. The
single laboratory lowest concentration MRL (LCMRL) is the lowest true concentration for
which the future recovery is predicted to fall, with high confidence (99%), between 50 and
150 percent recovery. The procedure used to determine the LCMRL is described elsewhere.1
1.3 Laboratories using this method are not required to determine LCMRLs, but must demonstrate
that the MRL for each analyte meets the requirements described in Section 9.2.4.
1.4 Determining the detection limit (DL) for analytes in this method is optional (Sect. 9.2.6).
Detection limit is defined as the statistically calculated minimum concentration that can be
measured with 99 percent confidence that the reported value is greater than zero.2 The DL is
compound dependent and is dependent on extraction efficiency, sample matrix, fortification
concentration, and instrument performance.
1.5 This method is intended for use by analysts skilled in the performance of solid phase
extractions, the operation of GC/MS instruments, and the interpretation of the associated data.
2. SUMMARY OF METHOD
2.1 A 1-liter water sample passed through a solid phase extraction (SPE) disk containing
polystyrenedivinylbenzene (SDVB) to extract the method analytes. Retained compounds are
eluted from the solid phase with a small amount of ethyl acetate (EtOAc) and methylene
chloride (MeCl2). The extract is dried by passing it through a column of anhydrous sodium
sulfate, concentrated with nitrogen, and then adjusted to a 1-mL volume with ethyl acetate.
Three internal standards are added to the final extract. The analytes are separated and
identified by GC/MS analysis. Analyte confirmation is accomplished by comparing the
analyte mass spectra and retention times to reference spectra and retention times for
calibration standards acquired under identical GC/MS conditions. The concentration of each
analyte is determined by using the internal standard technique. Surrogate analytes are added
to all field and quality control (QC) samples to monitor the extraction efficiency of the
method analytes.
3. DEFINITIONS
3.1 ANALYSIS BATCH ?A set of samples that is analyzed on the same instrument during a
24-hour period that begins and ends with the analysis of the appropriate Continuing Calibra-
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tion Check (CCC) Standards. Additional CCCs may be required depending on the length of
the Analysis Batch and the number of field samples.
3.2 CALIBRATION STANDARD (CAL) ?A solution prepared from the primary dilution
standard solution or stock standard solution(s) and the internal standards and surrogate
analytes. The CAL solutions are used to calibrate the instrument response with respect to
analyte concentration.
3.3 CONTINUING CALIBRATION CHECK (CCC) STANDARD ?A calibration standard
containing the method analytes, which is analyzed periodically to verify the accuracy of the
existing calibration for those analytes.
3.4 DETECTION LIMIT (DL) ?The minimum concentration of an analyte that can be identified,
measured and reported with 99 percent confidence that the analyte concentration is greater
than zero. This is a statistical determination (Sect. 9.2.6), and accurate quantitation is not
expected at this level.2
3.5 EXTRACTION BATCH ?A set of up to 20 field samples (not including QC samples)
extracted together by the same person(s) during a work day using the same lot of solid phase
extraction devices, solvents, surrogate solution, and fortifying solutions. Required QC
samples include Laboratory Reagent Blank, Laboratory Fortified Blank, Laboratory Fortified
Sample Matrix, and either a Field Duplicate or Laboratory Fortified Sample Matrix Duplicate.
3.6 FIELD DUPLICATES (FD1 and FD2) ?Two separate samples collected at the same time and
place under identical circumstances, and treated the same throughout field and laboratory
procedures. Field Duplicates are used to estimate the precision associated with sample
collection, preservation, and storage, as well as with laboratory procedures.
3.7 INTERNAL STANDARD (IS) ?A pure analyte added to an extract or standard solution in a
known amount and used to measure the relative responses of other method analytes and
surrogates. The internal standard must be an analyte that is not a sample component.
3.8 LABORATORY FORTIFIED BLANK (LFB) ?An aliquot of reagent water to which known
quantities of the method analytes and the preservation compounds are added. The LFB is
processed and analyzed exactly like a sample, and its purpose is to determine whether the
methodology is in control, and whether the laboratory is capable of making accurate and
precise measurements.
3.9 LABORATORY FORTIFIED SAMPLE MATRIX (LFSM) ?An aliquot of a field sample to
which known quantities of the method analytes and the preservation compounds are added.
The LFSM is processed and analyzed exactly like a sample, and its purpose is to determine
whether the sample matrix contributes bias to the analytical results. The background
concentrations of the analytes in the sample matrix must be determined in a separate aliquot
and the measured values in the LFSM corrected for background concentrations.
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3.10 LABORATORY FORTIFIED SAMPLE MATRIX DUPLICATE (LFSMD) ?A second
aliquot of the field sample used to prepare the LFSM, which is fortified, extracted and
analyzed identically to the LFSM. The LFSMD is used instead of the Field Duplicate to
access method precision and accuracy when the occurrence of a method analyte is infrequent.
3.11 LABORATORY REAGENT BLANK (LRB) ?An aliquot of reagent water that is treated
exactly as a sample including exposure to all glassware, equipment, solvents, reagents, sample
preservatives, internal standards, and surrogates that are used in the extraction batch. The
LRB is used to determine if method analytes or other interferences are present in the
laboratory environment, the reagents, or the apparatus.
3.12 MATERIAL SAFETY DATA SHEET (MSDS) ?Written information provided by vendors
concerning a chemical's toxicity, health hazards, physical properties, fire, and reactivity data
including storage, spill, and handling precautions.
3.13 LOWEST CONCENTRATION MINIMUM REPORTING LEVEL (LCMRL) ?The single-
laboratory LCMRL is the lowest true concentration for which the future recovery is predicted
to fall, with high confidence (99%), between 50 and 150 percent recovery.1
3.14 MINIMUM REPORTING LEVEL (MRL) ?The minimum concentration that can be reported
by a laboratory as a quantitated value for a method analyte in a sample following analysis.
This concentration must meet the criteria defined in Section 9.2.4.
3.15 PRIMARY DILUTION STANDARD SOLUTION (PDS) ?A solution containing method
analytes prepared in the laboratory from stock standard solutions and diluted as needed to
prepare calibration solutions and other analyte solutions.
3.16 QUALITY CONTROL SAMPLE (QCS) 瑼 sample prepared using a PDS of method analytes
that is obtained from a source external to the laboratory and different from the source of
calibration standards. The QCS is used to check calibration standard integrity.
3.17 STOCK STANDARD SOLUTION (SSS) ?A concentrated solution containing one or more
method analytes prepared in the laboratory using assayed reference materials or purchased
from a reputable commercial source.
3.18 SURROGATE ANALYTE (SUR) ?A pure analyte, which is extremely unlikely to be found
in any sample, and which is added to a sample aliquot in a known amount before extraction or
other processing, and is measured with the same procedures used to measure other sample
components. The purpose of the SUR is to monitor method performance with each sample.
4. INTERFERENCES
4.1 All glassware must be meticulously cleaned. Wash glassware with detergent and tap water;
rinse with tap water, followed by reagent water. Finally, rinse with methanol or acetone.
Non-volumetric glassware can be heated in a muffle furnace at 400 癈 for 2 hours as a
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substitute for a solvent rinse. Volumetric glassware should not be heated in an oven above
120 癈.
4.2 Method interferences, introduced from contaminants in solvents, reagents (including reagent
water), sample bottles and caps, and other sample processing hardware, may cause discrete
artifacts and/or elevated baselines in the chromatograms. All items such as these must be
routinely demonstrated to be free from interferences (less than 1/3 the MRL for each method
analyte) under the conditions of the analysis by analyzing Laboratory Reagent Blanks as
described in Section 9.3.1. Subtracting blank values from sample results is not permitted.
4.3 Matrix interferences may be caused by contaminants that are co-extracted from the sample.
The extent of matrix interferences will vary considerably from source to source, depending
upon the nature of the water. Water samples high in total organic carbon (TOC) may exhibit
an elevated baseline or interfering peaks.
4.4 Relatively large quantities of the buffer and preservatives (Sect. 8.1.2) are added to sample
bottles. The potential exists for trace-level organic contaminants in these reagents. Interfer-
ences from these sources should be monitored by analysis of Laboratory Reagent Blanks, par-
ticularly when new lots of reagents are acquired.
4.5 Solid phase extraction disks have been observed to be a source of interferences. The analysis
Laboratory Reagent Blanks can provide important information regarding the presence or
absence of such interferences. Brands and lots of solid phase extraction devices should be
tested to ensure that contamination does not preclude analyte identification and quantitation.
4.6 Silicone compounds may be leached from punctured septa of autosampler vials, particularly
when pieces of a septum fall into the solvent. This can occur after repeated injections from
the same autosampler vial. These silicone compounds, which appear as regularly spaced
chromatographic peaks with similar fragmentation patterns, can unnecessarily complicate the
total ion chromatograms and may cause interferences at high levels.
4.7 Quantitation of bromacil should be reviewed for potential common interferences. The
quantitation ion suggested in Section 17, Table 2 (m/z 205) may be present in compounds
leached from the SDVB media during extraction. Method blanks should be carefully
examined for this potential interference. The m/z 207 fragment may be used as an alternate
quantitation ion; however, this ion is associated with column bleed.
5. SAFETY
5.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely
defined. Each chemical should be treated as a potential health hazard, and exposure to these
chemicals should be minimized. Each laboratory is responsible for maintaining an awareness
of OSHA regulations regarding safe handling of chemicals used in this method. A reference
file of MSDSs should be made available to all personnel involved in the chemical analysis.
Additional references to laboratory safety are available.3-5
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5.2 Pure standard materials and stock standard solutions of these compounds should be handled
with suitable protection to skin and eyes, and care should be taken not to breathe the vapors or
ingest the materials.
6. EQUIPMENT AND SUPPLIES (All specifications are suggested. Catalog numbers are included
for illustration only.)
6.1 SAMPLE CONTAINERS ?1-liter amber glass bottles fitted with polytetrafluoroethylene
(PTFE)-lined screw caps.
6.2 VIALS ?Various sizes of amber glass vials with PTFE-lined screw caps for storing standard
solutions and extracts. Amber glass 2-mL autosampler vials with PTFE faced septa.
6.3 VOLUMETRIC FLASKS ?Class A, suggested sizes include 1, 5, and 10 mL for preparation
of standards and dilution of extract to final volume.
6.4 GRADUATED CYLINDERS ?Suggested sizes include 5, 10, and 250 mL.
6.5 MICRO SYRINGES ?Suggested sizes include 10, 25, 50, 100, 250, 500, and 1000 礚.
6.6 DRYING COLUMN ?The drying column must be able to contain 5 to 7 g of anhydrous
sodium sulfate (Na2SO4). The drying column should not leach interfering compounds or
irreversibly adsorb method analytes. Any small glass column may be used, such as a glass
pipette with glass wool plug (Chase Scientific Glass, Inc. P1005, 4.5 mL Monstr-Pette or
equivalent).
6.7 CONICAL COLLECTION TUBES ?50 mL, or other glassware (Fisher Cat. No.: 05-569-
6C) suitable for collection of the eluent from the solid phase disk after extraction and for
collecting extract from drying tube.
6.8 ANALYTICAL BALANCE ?Capable of weighing to the nearest 0.0001 g.
6.9 SOLID PHASE EXTRACTION (SPE) APPARATUS USING DISKS
6.9.1 SPE DISKS ?47-mm diameter and 0.5-mm thick, manufactured with a
polystyrenedivinylbenzene (SDVB) sorbent phase (Varian Cat. No.: 1214-5010 or
equivalent).
6.9.2 SPE DISK EXTRACTION GLASSWARE ?Funnel, PTFE-coated support screen, PTFE
gasket, base, and clamp used to support SPE disks and contain samples during extraction.
May be purchased as a set (Fisher Cat. No.: K971100-0047 or equivalent) or separately.
6.9.3 VACUUM EXTRACTION MANIFOLD ?Designed to accommodate extraction
glassware and disks (Varian Cat. No.: 1214-6001 or equivalent).
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6.9.4 An automatic or robotic system designed for use with SPE disks may be used if all
quality control requirements discussed in Section 9 are met. Automated systems may use
either vacuum or positive pressure to process samples and solvents through the disk. All
extraction and elution steps must be the same as in the manual procedure. Extraction
and/or elution steps may not be changed or omitted to accommodate the use of an
automated system.
6.10 EXTRACT CONCENTRATION SYSTEM ?Extracts are concentrated by blowdown with
nitrogen using water bath set at 40 癈 (N-Evap, Model 11155, Organomation Associates, Inc.,
or equivalent).
6.11 LABORATORY OR ASPIRATOR VACUUM SYSTEM ?Sufficient capacity to maintain a
vacuum of approximately 15 to 25 inches of mercury (Hg) for extraction disks.
6.12 GAS CHROMATOGRAPH/MASS SPECTROMETER (GC/MS) SYSTEM
6.12.1 FUSED SILICA CAPILLARY GC COLUMN ?30 m x 0.25-mm inside diameter (i.d.)
fused silica capillary column coated with a 0.25 祄 bonded film of 5%-diphenyl-95%-
dimethylpolysiloxane (Agilent HP-5MS or equivalent). Any capillary column that
provides adequate capacity, resolution, accuracy, and precision as summarized in Section
17 may be used. A nonpolar, low-bleed column is recommended for use with this
method to provide adequate separation and minimize column bleed.
6.12.2 GC INJECTOR AND OVEN ?Equipped for split/splitless injection. Some of the
method analytes, such as the brominated diphenyl ethers (BDEs), are subject to thermal
breakdown in the injector port. The injection system must not allow analytes to contact
hot stainless steel or other metal surfaces that promote decomposition. The performance
data in Section 17 were obtained using splitless injection and a 2-mm i.d. glass
deactivated liner (Agilent Cat. No.: 5181-8818) at a temperature optimized to avoid
thermal decomposition. Other injection techniques such as temperature programmed
injections, cold on-column injections and large volume injections may be used if the QC
criteria in Section 9 are met. Equipment designed appropriately for these alternate types
of injections must be used if these options are selected.
6.12.3 GC/MS INTERFACE ?Interface should allow the capillary column or transfer line exit
to be placed within a few millimeters of the ion source. Other interfaces, such as jet
separators, are acceptable as long as the system has adequate sensitivity and QC
performance criteria are met.
6.12.4 MASS SPECTROMETER ?The MS must be capable of electron ionization at a nominal
electron energy (70 eV is recommended) to produce positive ions. The spectrometer
must be capable of scanning at a minimum from m/z 45 to 650 with a complete scan
cycle time (including scan overhead) of 1.0 second or less. The spectrometer should
produce a mass spectrum that meets all criteria in Table 1 (Sect. 17) when a solution
containing approximately 5 ng of decafluorotriphenylphosphine (DFTPP) is injected into
the GC/MS. The scan time should be set so that all analytes have a minimum of at least
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five scans across the chromatographic peak. Ten to 15 scans across chromatographic
peaks are recommended.
6.12.5 DATA SYSTEM ?An interfaced data system is required to acquire, store, and output MS
data. The computer software should have the capability of processing GC/MS data by
recognizing a GC peak within a given retention time window. The software must allow
integration of the ion abundance of any specific ion between specified time or scan
number limits. The software must be able to calculate analyte concentrations using
relative response factors (RRFs), or by constructing linear and quadratic calibration
curves.
7. REAGENTS AND STANDARDS
7.1 REAGENTS AND SOLVENTS ?Reagent grade or better chemicals should be used in all
tests. Unless otherwise indicated, it is intended that all reagents will conform to the
specifications of the Committee on Analytical Reagents of the American Chemical Society
(ACS), where such specifications are available. Other grades may be used if all the
requirements of the Initial Demonstration of Capability (IDC) are met when using these
reagents.
7.1.1 HELIUM ?99.999 percent or better, GC carrier gas.
7.1.2 REAGENT WATER ?Purified water which does not contain any measurable quantities
of any method analytes or interfering compounds at or above 1/3 the MRL for each
compound of interest.
7.1.3 METHANOL (MeOH) (CASRN 67-56-1) ?High purity, demonstrated to be free of
analytes and interferences (Fisher, GC Resolve Grade or equivalent).
7.1.4 ETHYL ACETATE (EtOAc) (CASRN 141-78-6) ?High purity, demonstrated to be free
of analytes and interferences (B&J Brand? High Purity Solvent Grade or equivalent).
7.1.5 METHYLENE CHLORIDE (MeCl2) (CASRN 75-09-02) ?High purity, demonstrated to
be free of analytes and interferences (B&J Brand GC2? Capillary GC/GC-MS Grade or
equivalent).
7.1.6 SODIUM SULFATE (Na2SO4), ANHYDROUS (CASRN 7757-82-6) ?Soxhlet
extracted with methylene chloride for a minimum of four hours or heated to 400 癈 for
two hours in a muffle furnace. An "ACS grade, suitable for pesticide residue analysis,"
or equivalent, of anhydrous sodium sulfate is recommended.
7.1.7 SAMPLE PRESERVATION REAGENTS ?These preservatives are solids at room
temperature and may be added to the sample bottle before shipment to the field.
7.1.7.1 POTASSIUM DIHYDROGEN CITRATE (CASRN 866-83-1) ?The sample must
be buffered to pH 3.8 to inhibit microbial growth and analyte degradation.
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7.1.7.2 L-ASCORBIC ACID (CASRN 50-81-7) ?Ascorbic acid reduces "free chlorine" at
the time of sample collection.
7.1.7.3 ETHYLENEDIAMINETETRAACETIC ACID (EDTA), TRISODIUM SALT
(CASRN 10378-22-0) ?Trisodium EDTA is added to inhibit metal-catalyzed
hydrolysis of analytes.
7.2 STANDARD SOLUTIONS ?If the purity of a neat compound is 96 percent or greater, the
weight can be used without correction to calculate the concentration of the stock standard.
Solution concentrations listed in this section were used to develop this method and are
included as examples. Standards for sample fortification generally should be prepared in the
smallest volume that can be accurately measured to minimize the addition of excess organic
solvent to aqueous samples. Even though stability times for standard solutions are
suggested in the following sections, laboratories should use standard QC practices to
determine when standards need to be replaced.
7.2.1 INTERNAL STANDARD (IS) SOLUTIONS ?This method uses three internal standard
compounds listed in the table below.
Internal Standards CASRN
acenaphthene-d10 15067-26-2
phenanthrene-d10 1517-22-2
chrysene-d12 1719-03-5
7.2.1.1 INTERNAL STANDARD PRIMARY DILUTION STANDARD (Internal Standard
PDS) (500 礸/mL) ?Prepare, or purchase commercially, the Internal Standard
Primary Dilution Standard at a concentration of 500 礸/mL. If prepared from neat
or solid materials, this solution requires the preparation of a more concentrated
stock standard similar to the procedure followed for the analyte stock (Sect.
7.2.3.1). The Internal Standard PDS used in these studies was purchased in
acetone. The Internal Standard PDS is stable for 1 year in amber glass, screw-cap
vials when stored at -10 癈or less. Use 10 礚 of this 500-礸/mL solution to fortify
the final 1-mL extracts (Sect. 11.3.7). This will yield a concentration of 5 礸/mL
for each internal standard.
7.2.2 SURROGATE (SUR) ANALYTE STANDARD SOLUTIONS ?The three surrogates
for this method are listed in the table below.
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Surrogates CASRN
1,3-dimethyl-2-nitrobenzene 81-20-9
triphenylphosphate 115-86-6
perylene-d12 1520-96-3
7.2.2.1 SURROGATE PRIMARY DILUTION STANDARD (SUR PDS) (500 礸/mL) ?br>
Either purchase a SUR PDS from a commercial source or prepare from the neat
materials at a concentration of 500 礸/mL. The Surrogate PDS used in these
studies was purchased in acetone. This solution is used to fortify all QC and field
samples. The SUR PDS is stable for 1 year when stored in amber glass, screw-cap
vials at -10 癈or less.
7.2.3 ANALYTE STANDARD SOLUTIONS ?Obtain the analytes listed in the table in
Section 1.1 as neat materials or as commercially prepared ampulized solutions from a
reputable standard manufacturer. Two separate analyte stock solutions will need to be
prepared, one to fortify LFBs, LFSMs, and LFSMDs (Analyte Fortification Solution),
and one to prepare the CAL standards (Analyte Primary Dilution Standard). The Analyte
Fortification Standard is diluted with methanol prior to spiking water samples. This
avoids potential bias in the fortified samples as noted in Section 7.2.3.3. The Analyte
Primary Dilution Standard is diluted in ethyl acetate to be consistent with the sample
extract composition. Prepare the analyte stock and Primary Dilution Standards as
described below.
7.2.3.1 ANALYTE STOCK STANDARD SOLUTIONS (0.25 to 1.0 mg/mL) ?Analyte
standards may be purchased commercially as ampulized solutions (AccuStandard
Mix 1, Cat. No.: M-527-BDE; Mix 2, M-527-PEST-A; and Mix 3, M-527-PEST-B
or equivalent), or prepared from neat materials. Mix 1 and 2 were prepared in
methanol. Mix 3, which contains the BDEs and hexabromobiphenyl, was prepared
in isooctane:ethyl acetate (4:1). Stock standards are stable for six months when
stored in amber glass, screw-cap vials at -10 癈or less.
7.2.3.2 ANALYTE PRIMARY DILUTION STANDARD (50 礸/mL) ?Prepare the
50-礸/mL Analyte PDS by volumetric dilution of the Analyte Stock Standard
solution (Sect. 7.2.3.1) in ethyl acetate to make a 50-礸/mL solution. The Analyte
PDS is used to prepare calibration solutions. Care should be taken during storage to
prevent evaporation. The Analyte PDS is stable for six months when stored in
amber glass, screw-cap vials at -10 癈or less.
7.2.3.3 ANALYTE FORTIFICATION SOLUTION (5.0 to 50 礸/mL) ?The Analyte
Fortification Solution contains all method analytes of interest in methanol. It is
prepared by dilution of the Analyte Stock Standard and is used to fortify the LFBs,
the LFSMs and the LFSMDs with method analytes. It is recommended that three
concentrations be prepared so that the fortification levels can be rotated. The
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Analyte Fortification Solutions are stable for six months when stored in amber
glass, screw-cap vials at -10 癈or less.
NOTE: The Analyte Stock Standard must be diluted with methanol to create the
Analyte Fortification Solution. Decreased recoveries of Dimethoate were observed
when the LFB, LFSM, and the LFSMD were fortified with a solution that was
diluted in ethyl acetate. Recoveries as low as 35% were observed for Dimethoate
when as little as 200 礚 of ethyl acetate was used to fortify the method analytes in
the 1-L water samples.
7.2.4 CALIBRATION SOLUTIONS ?Prepare at least five standards over the concentration
range of interest from dilutions of the Analyte PDS in ethyl acetate. All calibration
solutions should contain at least 80 percent ethyl acetate so that gas chromatographic
performance is not compromised. The lowest concentration calibration standard must be
at or below the MRL. A constant concentration of each internal standard and surrogate
(in the range of 2 to 5 ng/礚) is added to each calibration standard. For method
development work, 10 礚 of the 500-礸/mL Internal Standard PDS and 10 礚 of the
500-礸/mL SUR PDS were added to each calibration standard to yield a final
concentration of 5 礸/mL for each. The calibration solutions are stable for six months
when stored in amber glass, screw-cap vials at -10 癈or less.
Cal Vol. 50 礸/mL Vol. 500 Vol. 500 Final Vol. Final Conc.
Analyte PDS 礸/mL IS 礸/mL SUR CAL Std. Analytes
Level
a
(uL) PDS (礚) PDS (礚) (礚) (礸/mL)
1 5.0 10.0 10.0 1000 0.25
2 10.0 10.0 10.0 1000 0.50
3 20.0 10.0 10.0 1000 1.00
4 40.0 10.0 10.0 1000 2.00
5 100.0 10.0 10.0 1000 5.00
6 200.0 10.0 10.0 1000 10.00
a. Concentration of surrogates (SURs) and internal standards (IS) is 5 礸/mL.
7.2.5 GC/MS TUNE CHECK SOLUTION (5 礸/mL) (CASRN 5074-71-5) ?Prepare a
solution of DFTPP in MeCl2. DFTPP is more stable in methylene chloride than in
acetone or ethyl acetate. Store this solution in an amber glass, screw-cap vial at -10 篊 or
less.
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8. SAMPLE COLLECTION, PRESERVATION, AND STORAGE
8.1 SAMPLE BOTTLE PREPARATION
Grab samples must be collected in accordance with conventional sampling practices6
8.1.1
using 1-liter amber bottles fitted with PTFE-lined screw caps. Some of the pyrethroid
compounds photodegrade.
8.1.2 Preservation reagents, listed in the table below, are added to each sample bottle prior to
shipment to the field (or prior to sample collection).
Compound Amount Purpose
L-Ascorbic acid 0.10 g/L Dechlorination
Ethylenediaminetetraacetic acid, 0.35 g/L Inhibit metal-catalyzed hydrolysis of
trisodium salt method analytes
Potassium dihydrogen citrate 9.4 g/L pH 3.8 buffer mixture, microbial
inhibitor
8.1.2.1 Residual chlorine must be reduced at the time of sample collection with 100 mg of
ascorbic acid per liter. Sodium thiosulfate and sodium sulfite cannot be used
because they degrade method analytes. Sodium thiosulfate produces an extraneous
sulfur peak, requiring more frequent instrument maintenance.
8.1.2.2 Trisodium EDTA (0.35 g/L) must be added to inhibit metal-catalyzed hydrolysis of
the method analytes, principally, Esbiol, Thiazopyr, Malathion, Chlorpyrifos,
Thiobencarb, Parathion, Terbufos-Sulfone, Vinclozolin, Atrazine, and Propazine.
8.1.2.3 The sample must be buffered to pH 3.8 using potassium dihydrogen citrate (9.4
g/L). This treatment inhibits microbial degradation of analytes and reduces base-
catalyzed hydrolysis of some of the method analytes.
8.2 SAMPLE COLLECTION
8.2.1 Open the tap and allow the system to flush until the water temperature has stabilized
(approximately 3 to 5 minutes). Collect samples from the flowing system.
8.2.2 When sampling from an open body of water, fill a 1-L (or 1-quart) wide-mouth bottle or
1-L beaker with water sampled from a representative area, and carefully fill sample
bottles from the container. Sampling equipment, including automatic samplers, must be
free of plastic tubing, gaskets, and other parts that may leach interfering analytes into the
water sample.
8.2.3 Fill sample bottles, taking care not to flush out the sample preservation reagents.
Samples do not need to be collected headspace free.
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8.2.4 After collecting the sample, cap the bottle and mix until preservatives are dissolved.
Keep the sample sealed from time of collection until extraction.
8.3 SAMPLE SHIPMENT AND STORAGE ?Samples must be chilled during shipment and
must not exceed 10 癈 during the first 48 hours after collection. Sample temperature must be
confirmed to be at or below 10 癈 when they are received at the laboratory. Samples stored in
the lab must be held at or below 6 癈 until extraction, but should not be frozen.
8.4 SAMPLE AND EXTRACT HOLDING TIMES ?Results of the sample storage stability
study (Sect. 17, Table 7) indicated that the compounds listed in this method have adequate
stability for 14 days when collected, dechlorinated, preserved, shipped and stored as described
in Sections 8.1, 8.2, and 8.3. Water samples should be extracted as soon as possible but must
be extracted within 14 days. Extracts must be stored at 0 癈 or less and analyzed within 28
days after extraction. The extract storage stability study data are presented in Section 17,
Table 8.
9. QUALITY CONTROL
9.1 QC requirements include the Initial Demonstration of Capability (IDC) and ongoing QC
requirements. This section describes each QC parameter, their required frequency, and the
performance criteria that must be met in order to meet EPA quality objectives. The QC
criteria discussed in the following sections are summarized in Section 17, Tables 9 and 10.
These QC requirements are considered the minimum acceptable QC criteria. Laboratories are
encouraged to institute additional QC practices to meet their specific needs.
9.1.1 METHOD MODIFICATIONS ?The analyst is permitted to modify GC columns, GC
conditions, evaporation techniques, internal standards or surrogate standards, and MS
conditions. However, each time such method modifications are made, the analyst must
repeat the procedures of the IDC.
9.2 INITIAL DEMONSTRATION OF CAPABILITY ?The IDC must be successfully performed
prior to analyzing any field samples. Prior to conducting the IDC, the analyst must first
generate an acceptable initial calibration following the procedure outlined in Section 10.2.
9.2.1 INITIAL DEMONSTRATION OF LOW SYSTEM BACKGROUND ?Any time a new
lot of SPE disks is used, it must be demonstrated that a Laboratory Reagent Blank is
reasonably free of contamination and that the criteria in Section 9.3.1 are met.
9.2.2 INITIAL DEMONSTRATION OF PRECISION ?Prepare, extract, and analyze four to
seven replicate LFBs fortified near the midrange of the initial calibration curve according
to the procedure described in Section 11. Sample preservatives as described in Section
8.1.2 must be added to these samples. The relative standard deviation (RSD) of the
results of the replicate analyses must be less than 20 percent.
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9.2.3 INITIAL DEMONSTRATION OF ACCURACY ?Using the same set of replicate data
generated for Section 9.2.2, calculate average recovery. The average recovery of the
replicate values must be within ?30 percent of the true value.
9.2.4 MINIMUM REPORTING LEVEL (MRL) CONFIRMATION ?Establish a target
concentration for the MRL based on the intended use of the method. Establish an initial
calibration following the procedure outlined in Section 10.2. The lowest calibration
standard used to establish the initial calibration (as well as the low-level Continuing
Calibration Check standard) must be at or below the concentration of the MRL.
Establishing the MRL concentration too low may cause repeated failure of ongoing QC
requirements. Confirm the MRL following the procedure outlined below.
9.2.4.1 Fortify, extract, and analyze seven replicate Laboratory Fortified Blanks at the
proposed MRL concentration. These LFBs must contain all method preservatives
described in Section 8. Calculate the mean (Mean) and standard deviation for these
replicates. Determine the Half Range for the prediction interval of results (HRPIR)
using the equation below
HR PIR 3.963S
where S is the standard deviation, and 3.963 is a constant value for seven
replicates.1
9.2.4.2 Confirm that the upper and lower limits for the Prediction Interval of Result (PIR =
Mean + HRPIR) meet the upper and lower recovery limits as shown below.
The Upper PIR Limit must be < 150 percent recovery.
Mean HRPIR
100% 150%
FortifiedConcentration
The Lower PIR Limit must be > 50 percent recovery.
Mean HRPIR
100% 50%
FortifiedConcentration
9.2.4.3 The MRL is validated if both the Upper and Lower PIR Limits meet the criteria
described above (Sect. 9.2.4.2). If these criteria are not met, the MRL has been set
too low and must be determined again at a higher concentration.
9.2.5 CALIBRATION CONFIRMATION ?Analyze a Quality Control Sample as described in
Section 9.3.9 to confirm the accuracy of the primary calibration standards.
9.2.6 DETECTION LIMIT DETERMINATION (optional) -- While DL determination is not a
specific requirement of this method, it may be required by various regulatory bodies
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associated with compliance monitoring. It is the responsibility of the laboratory to
determine if DL determination is required based upon the intended use of the data.
Replicate analyses for this procedure should be done over at least three days (both the
sample extraction and the GC analyses should be done over at least three days). Prepare
at least seven replicate LFBs at a concentration estimated to be near the DL. This
concentration may be estimated by selecting a concentration at 2-5 times the noise level.
The DLs in Table 3 (Sect. 17) were calculated from LFBs fortified at various
concentrations as indicated in the table. The appropriate fortification concentrations will
be dependent upon the sensitivity of the GC/MS system used. All preservation reagents
listed in Section 8.1.2 must also be added to these samples. Analyze the seven replicates
through all steps of Section 11.
NOTE: If an MRL confirmation data set meets these requirements, a DL may be
calculated from the MRL confirmation data, and no additional analyses are necessary.
Calculate the DL using the following equation
DL s t
(n 1, 1 0.99)
where:
t (n-1, 1-=0.99) = Student's t value for the 99% confidence level with n-1 degrees of
freedom
n = number of replicates
s = standard deviation of replicate analyses.
NOTE: Do not subtract blank values when performing DL calculations.
9.3 ONGOING QC REQUIREMENTS ?This section summarizes the ongoing QC criteria that
must be followed when processing and analyzing field samples.
9.3.1 LABORATORY REAGENT BLANK (LRB) ?An LRB is required with each extraction
batch to confirm that potential background contaminants are not interfering with the
identification or quantitation of method analytes. If the LRB produces a peak within the
retention time window of any analyte that would prevent the determination of that
analyte, determine the source of contamination and eliminate the interference before
processing samples. Background contamination must be reduced to an acceptable level
before proceeding. Background from method analytes or other contaminants that inter-
fere with the measurement of method analytes must be below 1/3 of the MRL. (Blank
contamination may be estimated by extrapolation if the concentration is below the lowest
calibration standard. Note: Use of results below the MRL is not permitted for field
samples.) If analytes are detected in the LRB at concentrations equal to or greater than
the MRL, then all data for the problem analytes must be considered invalid for all
samples in the extraction batch.
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9.3.2 CONTINUING CALIBRATION CHECK (CCC) ?CCC standards are analyzed at the
beginning of each Analysis Batch, after every ten field samples, and at the end of the
Analysis Batch. See Section 10.3 for concentration requirements and acceptance criteria.
9.3.3 LABORATORY FORTIFIED BLANK (LFB) ?An LFB is required with each extraction
batch. The fortified concentration of the LFB must be rotated between low, medium, and
high concentrations from batch to batch. The low concentration LFB must be as near as
practical to, but no more than two times the MRL. Similarly, the high concentration LFB
should be near the high end of the calibration range established during the initial cal-
ibration (Sect. 10.2). Results of the low-level LFB analyses must be 50 to 150 percent of
the true value. Results of the mid- and high-level LFB analyses must be 70 to
130 percent of the true value. If the LFB results do not meet these criteria, then all data
for the problem analytes must be considered invalid for all samples in the extraction
batch.
9.3.4 MS TUNE CHECK ?A complete description of the MS Tune Check is found in Section
10.2.1. Acceptance criteria for the MS Tune Check are summarized in Table 1 (Sect. 17).
The MS Tune Check must be performed each time a major change is made to the mass
spectrometer, and prior to each initial calibration (Sect. 10.2). Daily DFTPP analysis is
not required.
9.3.5 INTERNAL STANDARDS (IS) ?The analyst must monitor the peak area of the IS in all
injections during each Analysis Batch. The IS response (peak area) in any
chromatographic run must not deviate from the response in the most recent CCC by more
than 30%, and must not deviate by more than 50% from the area measured during initial
analyte calibration. If the IS area in a chromatographic run does not meet these criteria,
inject a second aliquot of that extract.
9.3.5.1 If the reinjected aliquot produces an acceptable internal standard response, report
results for that aliquot.
9.3.5.2 If the reinjected extract fails again, the analyst should check the calibration by
reanalyzing the most recently acceptable CCC. If the CCC fails the criteria of
Section 10.3, recalibration is in order per Section10.2. If the CCC is acceptable,
extraction of the sample may need to be repeated provided the sample is still within
the holding time. Otherwise, report results obtained from the reinjected extract, but
annotate as suspect. Alternatively, collect a new sample and reanalyze.
9.3.6 SURROGATE RECOVERY ?The surrogate standard is fortified into the aqueous
portion of all samples, LRBs, LFSMs, and LFSMDs prior to extraction. It is also added
to the calibration standards. Calculate the recovery (%R) for the surrogate using the
equation
A
% R 100
B
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where A = calculated surrogate concentration for the QC or field sample, and B =
fortified concentration of the surrogate.
9.3.6.1 Surrogate recovery must be in the range of 70 to 130%. When surrogate recovery
from a sample, blank, or CCC is less than 70 percent or greater than 130 percent,
check 1) calculations to locate possible errors, 2) standard solutions for degradation,
3) contamination, and 4) instrument performance. Correct the problem and
reanalyze the extract.
9.3.6.2 If the extract reanalysis meets the surrogate recovery criterion, report only data for
the reanalyzed extract.
9.3.6.3 If the extract reanalysis fails the 70 to 130 percent recovery criterion, the analyst
should check the calibration by injecting the last CCC that passed. If the CCC fails
the criteria of Section 9.3.6.1., recalibration is in order per Section 10.2. If the CCC
is acceptable, extraction of the sample should be repeated provided the sample is
still within the holding time. If the re-extracted sample also fails the recovery
criterion, report all data for that sample as "suspect/surrogate recovery" to inform
the data user that the results are suspect due to surrogate recovery.
9.3.7 LABORATORY FORTIFIED SAMPLE MATRIX (LFSM) ?Analysis of an LFSM is
required in each extraction batch. If a variety of different sample matrices are analyzed
regularly, for example, drinking water from groundwater and surface water sources,
method performance should be established for each. Over time, LFSM data should be
documented for all routine sample sources for the laboratory.
9.3.7.1 Within each extraction batch, a minimum of one field sample is fortified as an
LFSM for every 20 samples extracted. The LFSM is prepared by spiking a sample
with an appropriate amount of the Analyte Fortification Solution (Sect. 7.2.3.3).
Select a spiking concentration that is greater than or equal to the matrix background
concentration, if known. Use historical data and rotate through various
concentrations when selecting a fortifying concentration.
9.3.7.2 Calculate the percent recovery (%R) for each analyte using the equation
A B 100
%R
C
where A = measured concentration in the fortified sample, B = measured
concentration in the unfortified sample, and C = fortification concentration.
9.3.7.3 Analyte recoveries may exhibit matrix bias. For samples fortified at or above their
native concentration, recoveries should range between 70 and 130 percent, except
for low-level fortification near or at the MRL (within a factor of two times the MRL
concentration) where 50 to 150 percent recoveries are acceptable. If the accuracy
of any analyte falls outside the designated range, and the laboratory performance for
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that analyte is shown to be in control in the CCCs, the recovery is judged to be ma-
trix biased. The result for that analyte in the unfortified sample is labeled "suspect/
matrix" to inform the data user that the results are suspect due to matrix effects.
9.3.8 FIELD DUPLICATE OR LABORATORY FORTIFIED SAMPLE MATRIX
DUPLICATE (FD or LFSMD) ?Within each extraction batch, a minimum of one Field
Duplicate (FD) or Laboratory Fortified Sample Matrix Duplicate (LFSMD) must be
analyzed. Duplicates check the precision associated with sample collection, preservation,
storage, and laboratory procedures. If method analytes are not routinely observed in field
samples, an LFSMD should be analyzed rather than an FD.
9.3.8.1 Calculate the relative percent difference (RPD) for duplicate measurements (FD1
and FD2) using the equation
FD1 FD 2
RPD 100
FD1 FD 2 / 2
9.3.8.2 RPDs for Field Duplicates should be less than or equal to 30 percent. Greater
variability may be observed when Field Duplicates have analyte concentrations that
are within a factor of 2 of the MRL. At these concentrations, Field Duplicates
should have RPDs that are less than or equal to 50 percent. If the RPD of any
analyte falls outside the designated range, and the laboratory performance for that
analyte is shown to be in control in the CCC, the recovery is judged to be matrix
biased. The result for that analyte in the unfortified sample is labeled
"suspect/matrix" to inform the data user that the results are suspect due to matrix
effects.
9.3.8.3 If an LFSMD is analyzed instead of a Field Duplicate, calculate the relative percent
difference (RPD) for duplicate LFSMs (LFSM and LFSMD) using the equation
LFSM LFSMD
RPD 100
LFSM LFSMD / 2
9.3.8.4 RPDs for duplicate LFSMs should be less than or equal to 30 percent. Greater
variability may be observed when LFSMs are fortified at analyte concentrations that
are within a factor of 2 of the MRL. LFSMs fortified at these concentrations should
have RPDs that are less than or equal to 50 percent. If the RPD of any analyte falls
outside the designated range, and the laboratory performance for that analyte is
shown to be in control in the CCC, the recovery is judged to be matrix biased. The
result for that analyte in the unfortified sample is labeled "suspect/matrix" to inform
the data user that the results are suspect due to matrix effects.
9.3.9 QUALITY CONTROL SAMPLES (QCS) ?As part of the IDC (Sect. 9.2), each time a
new Analyte PDS (Sect. 7.2.3.2) is prepared, and at least quarterly, analyze a QCS
sample from a source different from the source of the calibration standards. If a second
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vendor is not available then a different lot of the standard should be used. The QCS
should be prepared and analyzed as a CCC. Acceptance criteria for the QCS are identical
to the mid-level CCC; the calculated amount for each analyte must be ?30 percent of the
expected value. If measured analyte concentrations are not of acceptable accuracy, check
the entire analytical procedure to locate and correct the problem.
10. CALIBRATION AND STANDARDIZATION
10.1 Demonstration and documentation of acceptable mass spectrometer tune and initial calibration
is required before any samples are analyzed. After the initial calibration is successful, a
Continuing Calibration Check is required at the beginning and end of each period in which
analyses are performed, and after every tenth sample. Verification of mass spectrometer tune
must be repeated each time a major instrument modification is made or maintenance is
performed, and prior to analyte calibration.
10.2 INITIAL CALIBRATION
10.2.1 MS TUNE/MS TUNE CHECK?Calibrate the mass and abundance scales of the MS with
calibration compounds and procedures prescribed by the manufacturer with any modifi-
cations necessary to meet tuning requirements. Inject 5 ng or less of the DFTPP solution
(Sect. 7.2.5) into the GC/MS system. Acquire a mass spectrum that includes data for m/z
45 to 450. Use a single spectrum of the DFTPP peak, an average spectrum of the three
highest points of the peak, or an average spectrum across the entire peak to evaluate the
performance of the system. If the DFTPP mass spectrum does not meet all criteria in
Table 1 (Sect. 17), the MS must be retuned and adjusted to meet all criteria before
proceeding with the initial calibration.
10.2.2 INSTRUMENT CONDITIONS ?Operating conditions are described below. Conditions
different from those described may be used if QC criteria in Section 9 are met. Different
conditions include alternate GC columns, temperature programs, MS conditions, injection
volume, and injection techniques such as cold on-column, direct injection port liners and
large volume injection techniques.
10.2.2.1 Inject a 1-礚 aliquot into a hot, splitless injection port held at 250 癈 with a split
delay of 1 minute. The temperature program is as follows: initial oven temperature
of 55 癈, hold for 0 minutes, ramp at 20 癈/min to 200 癈, hold for 2 minutes, ramp
at 4 癈/min to a final temperature of 300 癈 and hold for 0.75 minute. Total run
time is approximately 35 minutes. Begin data acquisition at 4.4 minutes.
NOTE: The GC was operated in a constant flow rate mode at a rate of 1.4 mL per
minute and an initial head-pressure of 12.0 psi.
10.2.2.2 Target compounds can exhibit decreased sensitivity for low-level injections due to
degradation or irreversible adsorption in the injector port. Deactivated glass or
quartz inlet liners are recommended. Decrease in response for BDE-47, BDE-99,
BDE-100, BDE-153, Fenvalerate, Esfenvalerate, Hexazinone, Nitrophen,
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Norflurazon, and Parathion are generally a result of degradation or adsorption
occurring in the inlet liner or on the inlet seal. Decrease in response for the lower
molecular weight analytes such as Vinclozolin, Prometryn, Bromacil and
Chlorpyrifos can usually be attributed to degradation of the first meter of the GC
column.
10.2.2.3 MS Detection and Sensitivity ?Adjust the scan cycle time to measure at least five
or more spectra during the elution of each GC peak. Ten to 15 scans across each
GC peak are recommended. The scan range can be set from m/z 45 to 670 for the
entire chromatographic run provided that there are enough scans across each GC
peak at the MRL.
10.2.2.3.1 An alternate approach that was used during method development is to establish
two scan ranges. Acquire data from a suggested range of m/z 45 to 450 with a
total cycle time (including scan overhead time) of 1.0 second or less for the
first 19 minutes of the run. Adjust the scan range to m/z 45 to 670 for the final
16 minutes of the run. The analyst must ensure that the scan range is changed
just prior to the elution of the third internal standard peak (chrysene-d12).
10.2.3 CALIBRATION SOLUTIONS ?Prepare a set of at least five calibration standards as
described in Section 7.2.4. The lowest concentration calibration standard must be at or
below the MRL. The MRL must be confirmed using the procedure outlined in Section
9.2.4 after establishing the initial calibration. Acceptable calibration over a large
dynamic range, greater than about 40-fold, may require more than one calibration curve.
Each curve must contain at least five calibration standards. In addition, field samples
must be quantitated using the same number of curves over the same concentration range
used to collect the IDC data (Sect. 9.2).
10.2.4 CALIBRATION ?Calibrate the GC/MS system using the internal standard technique.
Concentrations may be calculated through the use of an average relative response factor
(RRF) or through the use of a calibration curve. Calculate the RRFs using the equation
( Ax )(Qis)
RRF
( Ais)(Qx )
where
Ax = integrated peak area of the analyte,
Ais = integrated peak area of the internal standard,
Qx = quantity of analyte injected in ng or concentration units, and
Qis = quantity of internal standard injected in ng or concentration units.
Average RRF calibrations may only be used if the RRF values over the calibration range
are relatively constant.
10.2.4.1 Suggested quantitation ions are designated in Table 2 (Sect. 17). Some of the
polybrominated diphenyl ethers have ions at higher mass that may offer better
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selectivity. Quantitation at high m/z values, however, can suffer from imprecision
due to mass defect associated with halogenated compounds on some mass
spectrometers. This is observed as irregular, jagged extracted ion peak shapes.
10.2.5 As an alternative to calculating average RRFs, use the GC/MS data system software to
generate a linear or quadratic calibration curve. Forcing the calibration curve through the
origin is not recommended. The data presented in this method were obtained using
quadratic fits.
10.2.6 CALIBRATION ACCEPTANCE CRITERIA ?Acceptance criteria for the calibration of
each analyte is determined by calculating the concentration of each analyte and surrogate
in each of the analyses used to generate the calibration curve or average RRF. Each
calibration point, except the lowest point, for each analyte, should calculate to be 70 to
130 percent of its true value. The lowest point should calculate to be 50 to 150 percent of
its true value.
10.3 CONTINUING CALIBRATION CHECK (CCC) ?The CCC verifies the initial calibration at
the beginning and end of each Analysis Batch, and after every tenth sample during an
Analysis Batch. In this context, a "sample" is considered to be a field sample. The LRBs,
LFBs, LFSMs, LFSMDs and CCCs are not counted as samples. The beginning CCC for each
Analysis Batch must be at or below the MRL in order to verify instrument sensitivity prior to
any analyses. If standards have been prepared such that all analytes are not in the same
calibration standard (or all low CAL points are not in the same CAL standard), it may be
necessary to analyze more than one CCC to meet this requirement. Subsequent CCCs should
alternate between a medium and high concentration.
10.3.1 Inject an aliquot of the CCC and analyze with the same conditions used during the initial
calibration.
10.3.2 Determine that the absolute areas of the quantitation ions of the internal standards have
not changed by more than ?30 percent from the average area measured during initial
calibration. If any IS area has changed by more this amount, remedial action must be
taken (Sect. 10.3.4).
10.3.3 Calculate the concentration of each analyte and surrogate in the check standard. The
calculated amount for each analyte for mid- and high-level CCCs must be ?30 percent of
the true value. The calculated amount for the lowest calibration level for each analyte,
which must be at a concentration less than or equal to the MRL, must be within ?50
percent of the true value. If these criteria are not met, then all data for the problem
analyte must be considered invalid, and remedial action (Sect. 10.3.4) should be taken.
Any field sample extracts that have been analyzed since the last acceptable CCC should
be reanalyzed after acceptable calibration has been restored, with the following
exception. If the CCC fails because the calculated concentration is greater than
130 percent, (150 percent for the low-level CCC) for a particular analyte, and field
sample extracts show no detection for that analyte, non-detects may be reported without
re-analysis.
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10.3.4 REMEDIAL ACTION ?Failure to meet CCC QC performance criteria may require
remedial action. Major maintenance such as cleaning the ion source, cleaning the mass
analyzer, replacing filament assemblies, replacing or shortening GC columns, etc.,
require returning to the initial calibration step (Sect. 10.2).
11. PROCEDURE
11.1 Important aspects of this analytical procedure include proper preparation of laboratory
glassware, sample containers (Sect. 4.1), and sample collection and storage (Sect. 8). This
section describes the procedures for sample preparation, solid phase extraction (SPE), and
extract analysis.
11.2 SAMPLE BOTTLE PREPARATION
11.2.1 Samples are preserved, collected and stored as presented in Section 8. All field and QC
samples must contain the preservatives listed in Section 8.1.2, including the LRB and
LFB. Before extraction, mark the level of the sample on the outside of the sample bottle
for later sample volume determination. If using weight to determine volume (Sect.
11.3.8), weigh the bottle with collected sample before extraction.
11.2.2 Add an aliquot of the SUR PDS (Sect. 7.2.2.1) to each sample to be extracted. For
method development work, a 10-礚 aliquot of the 500-礸/mL SUR PDS was added to 1
L for a final concentration of 5.0 礸/L.
11.2.3 If the sample is an LFB, LFSM, or LFSMD, add the necessary amount of Analyte Fortifi-
cation Solution (Sect. 7.2.3.3). Swirl each sample to ensure all components are mixed.
The Analyte Fortification Solution should be prepared in methanol for reasons stated in
Section 7.2.3.3.
11.2.4 Proceed with sample extraction using SPE disks (Sect. 11.3).
11.3 DISK SPE PROCEDURE ?The disk extraction procedure may be carried out in a manual
mode or by using a robotic or automatic sample preparation device. This section describes the
disk SPE procedure using the equipment outlined in Section 6.9 in its simplest, least
expensive mode without the use of a robotics system. The manual mode described below was
used to collect data presented in Section 17. The use of a robotics system is allowed;
however, extraction and/or elution steps may not be changed or omitted to accommodate the
use of an automated system.
11.3.1 SAMPLE PREPARATION ?Prepare the samples as described in Section 11.2.
11.3.2 DISK CLEANUP ?Assemble the extraction glassware onto the vacuum manifold,
placing disks on a support screen between the funnel and base. Add a 5-mL aliquot of a
1:1 mixture of EtOAc and MeCl2, drawing about half through the disk, and allowing the
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solvent to soak the disk for about a minute. Draw the remaining solvent through the disk
to waste until the disk is dry.
11.3.3 DISK CONDITIONING ?The conditioning step is critical for recovery of analytes and
can have a marked effect on method precision and accuracy. Once the conditioning has
begun, the disk must not go dry until the last portion of the sample passes, because ana-
lyte and surrogate recoveries may be affected. If the disk goes dry during the condition-
ing phase, the conditioning must be started over. The analyst should note premature
drying of the solid phase, because the sample may require re-extraction due to low surro-
gate (and analyte) recoveries. During conditioning, it is not unusual for the middle of the
solid phase disk to form a wrinkle. This typically does not adversely affect extraction.
11.3.3.1 CONDITIONING WITH METHANOL ?Add approximately 10 mL of MeOH to
each disk. Pull about 1 mL of MeOH through the disk and turn off the vacuum
temporarily to let the disk soak for about one minute. Draw most of the remaining
MeOH through the disk, but leave a layer of MeOH on the surface of the disk. The
disk must not be allowed to go dry from this point until the end of the sample
extraction.
11.3.3.2 CONDITIONING WITH WATER ?Follow the MeOH rinse with two 10-mL
aliquots of reagent water, being careful to keep the water level above the disk
surface. Turn off the vacuum.
11.3.4 DISK EXTRACTION ?Add the sample to the extraction funnel containing the
conditioned disk and turn on the vacuum (10 to 15 in. Hg). Do not let the disk go dry
before the entire sample volume is extracted. Drain as much water from the sample
container as possible. After the entire sample has passed, pull air through the disk by
maintaining full vacuum for 10 minutes. If the disk is dried for a period much longer
than 10 minutes, poor recovery for the surrogate 1,3-dimethyl-2-nitrobenzene could
occur. After drying, turn off and release the vacuum.
11.3.5 DISK ELUTION ?Detach the glassware base from the manifold without disassembling
the funnel from the base. Dry the underside of the base. Insert collection tubes into the
manifold to catch the extracts as they are eluted from the disk. The collection tube must
fit around the drip tip of the base to ensure collection of all the eluent. Reattach the base
to the manifold. Add 5 mL of EtOAc to the empty sample bottle and thoroughly rinse the
inside of the bottle. Transfer the EtOAc to the disk and, with vacuum, pull enough
EtOAc into the disk to soak the sorbent. Allow the solvent to soak the disk for about one
minute. Using a vacuum, pull the remaining solvent slowly through the disk into the
collection tube. Next, add 5 mL of MeCl2 to the empty sample bottle and thoroughly
rinse the inside of the bottle. Transfer the MeCl2 to the disk and, with vacuum, pull
enough methylene chloride into the disk to soak the sorbent. Allow the solvent to soak
the disk for about one minute. Pull the remaining solvent slowly through the disk into the
collection tube. Rinse the SPE funnel surface with a 5-mL aliquot of 1:1 EtOAc/MeCl2
and pull the solvent slowly through the disk into the collection tube. Repeat this last
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rinse of the SPE funnel. Detach glassware from manifold and remove collection tube
from the manifold.
11.3.6 DRYING OF THE EXTRACT ?Small amounts of residual water from the sample
container and solid phase may form an immiscible layer with the solvent in the extract.
Set up a drying column (Sect. 6.6) packed with about 5 to 7 grams of anhydrous sodium
sulfate. Pre-rinse the sodium sulfate column with about 2 mL of 1:1 EtOAc/MeCl2.
Place a clean collection tube that can hold at least 30 mL beneath the drying column.
Add the entire extract to the column and follow with two 3-mL aliquots of 1:1
EtOAc/MeCl2.
11.3.6.1 Extracts should be examined visually for water droplets after drying. Extracts that
contain water have been noted to rapidly degrade the inertness of the GC inlet and
the head of the GC column requiring much more frequent maintenance.
11.3.7 EXTRACT CONCENTRATION ?Concentrate the extract to about 0.7 mL under a
gentle stream of nitrogen in a warm water bath (~40 oC). Do not blow down samples to
less than 0.5 mL, because the most volatile compounds (Dimethoate, and 1,3-dimethyl-2-
nitrobenzene) will exhibit diminished recovery. Transfer the extract to a 1-mL
volumetric flask and add the internal standard (method development used 10 礚 of
500-礸/mL IS PDS; extract concentration of 5 礸/mL). Rinse the collection tube that
held the dried extract with small amounts of EtOAc and add to the volumetric flask to
bring the volume up to the 1-mL mark. Transfer to an autosampler vial.
11.3.8 SAMPLE VOLUME OR WEIGHT DETERMINATION ?Use a graduated cylinder to
measure the volume of water required to fill the original sample bottle to the mark made
prior to extraction (Sect. 11.2.1). Determine volume to the nearest 10 mL for use in the
final calculations of analyte concentration (Sect. 12.2). If using weight to determine
volume, reweigh empty sample bottle. From the weight of the original sample bottle
measured in Section 11.2.1, subtract the empty bottle weight. Use this value for analyte
concentration calculations in Section 12.2.
11.4 ANALYSIS OF SAMPLE EXTRACTS
11.4.1 Establish operating conditions as described in Section 10.2.2. Confirm that compound
separation and resolution are similar to those summarized in Table 2 and Figure 1 (Sect.
17).
11.4.2 Establish a valid initial calibration following the procedures outlined in Section 10.2 or
confirm that the calibration is still valid by running a CCC as described in Section 10.3.
If establishing an initial calibration for the first time, complete the IDC as described in
Section 9.2.
11.4.3 Establish an appropriate retention time window for each analyte, internal standard and
surrogate to identify them in QC and field sample chromatograms. Ideally, the retention
time window should be based on measurements of actual retention time variation for each
527-25
compound in standard solutions collected on each GC/MS over the course of time. The
suggested variation is plus or minus three times the standard deviation of the retention
time for each compound for a series of injections. The injections from the initial
calibration and from the IDC (Sect. 9.2) may be used to calculate a suggested window
size. However, the experience of the analyst should weigh heavily on the determination
of an appropriate retention window size.
11.4.4 Analyze aliquots of field and QC samples at appropriate frequencies (Sect. 9) with the
GC/MS conditions used to acquire the initial calibration and/or the CCC. At the conclu-
sion of data acquisition, use the same software that was used in the calibration procedure
to tentatively identify analyte peaks in the predetermined retention time windows.
11.4.5 COMPOUND CONFIRMATION ?Confirm each analyte by comparison of its mass
spectrum (after background subtraction if necessary) to a reference spectrum in the user-
created database.
11.4.5.1 In general, all ions that are present above 30 percent relative abundance in the mass
spectrum of the standard should be present in the mass spectrum of the sample
component and should agree within an absolute 20 percent. For example, if an ion
has a relative abundance of 30 percent in the standard spectrum, its abundance in
the sample spectrum should be in the range of 10 to 50 percent. Some ions,
particularly the molecular ion, are of special importance, and should be evaluated
even if they are below 30 percent relative abundance.
11.4.5.2 Confirmation is more difficult when sample components are not resolved
chromatographically and produce mass spectra containing ions contributed by more
than one analyte. When GC peaks obviously represent more than one sample
component (i.e., broadened peak with shoulder(s) or valley between two or more
maxima), appropriate analyte spectra and background spectra can be selected by
examining plots of characteristic ions. When analytes coelute (i.e., only one GC
peak is apparent), the identification criteria can be met but each analyte spectrum
will contain extraneous ions contributed by the coeluting compound.
12. DATA ANALYSIS AND CALCULATIONS
12.1 Identify method analytes present in the field and QC samples as described in Section 11.4.
Complete chromatographic resolution is not necessary for accurate and precise measurements
of analyte concentrations if unique ions with adequate intensities are available for
quantitation.
12.1.1 In validating this method, concentrations were calculated by measuring the characteristic
ions listed in Table 2 (Sect. 17). Other ions may be selected at the discretion of the
analyst.
12.2 Calculate analyte and surrogate concentrations, using the multipoint calibration established in
Section 10.2. Do not use CCCs to quantitate analytes in samples. Adjust the final analyte
527-26
concentrations to reflect the actual sample volume or weight determined in Section 11.3.8.
Field sample extracts that require dilution should be treated as described in Section 12.3.
12.3 EXCEEDING CALIBRATION RANGE ?Do not extrapolate beyond the established
calibration range. If an analyte result exceeds the range of the initial calibration curve, the
extract may be diluted with EtOAc, with the appropriate amount of internal standard added to
match the original level, and the diluted extract injected. Acceptable surrogate performance
(Sect. 9.3.6) should be determined from the undiluted sample extract. Incorporate the dilution
factor into final concentration calculations. The resulting sample should be documented as a
dilution, and MRLs should be adjusted accordingly.
.
12.4 Calculations must utilize all available digits of precision, but final reported concentrations
should be rounded to an appropriate number of significant figures (one digit of uncertainty),
typically two, and not more than three significant figures.
13. METHOD PERFORMANCE
13.1 PRECISION, ACCURACY, AND MINIMUM REPORTING LEVELS ?Tables for these
data are presented in Section 17. Lowest Concentration MRLs for each method analyte are
presented in Table 3. This involved preparing, extracting, and analyzing seven replicates at
five concentrations (0.1, 0.2, 0.35, 0.5, and 1.0 礸/L) and then calculating the LCMRL
following the procedure described in reference 1. Detection Limits (DLs) were determined
following the procedure outlined in Section 9.2.6. The DLs are included in Table 3 for
comparison. Single laboratory precision and accuracy data are presented in Tables 4-6.
13.2 POTENTIAL PROBLEM COMPOUNDS
13.2.1 MATRIX ENHANCED SENSITIVITY ?Fenvalerate, Esfenvalerate, Nitrophen,
Parathion and to a lesser extent, Norflurazon may exhibit "matrix-induced
chromatographic response enhancement."7-11 Recovery for compounds exhibiting matrix
enhancement exceed 100% in fortified extracts at low concentrations and in CCCs.
Matrix enhancement is caused by the absorption or thermal degradation of analytes in the
GC inlet region. Co-extracted compounds in the extract are thought to coat the surface
inside the inlet, deactivating sites that would otherwise promote decomposition or
adsorption. As a result, susceptible analytes degrade more when injected in a clean
solvent matrix than in a sample extract, and greater response will be observed for
analytes in sample extracts than in calibration solutions. If matrix enhancement occurs,
more frequent calibration will be required. Deactivated injection liners should be used
(Sect. 6.12.2). The analyst may also choose to condition the injection port after
maintenance by injecting a few aliquots of a field sample extract prior to establishing an
initial calibration. Preparation of calibration standards in clean sample extracts is not
allowed.
13.2.2 As the injector becomes fouled, the analyst may note a decrease in response for the later
eluting compounds. If routine maintenance of the inlet is neglected, the analyst may
527-27
experience difficulty meeting the low-level CCC recovery criteria (at the MRL
concentration) for these analytes.
13.2.3 Kepone occasionally exhibited recoveries below 70%. Dimethoate exhibited
unacceptable recoveries in LFSM if it was fortified using EtOAc solutions. For this
reason, the Analyte Fortification Solution must be prepared in methanol (Sect. 7.2.3.3).
13.3 SAMPLE STORAGE STABILITY STUDIES ?A storage stability study was conducted by
fortifying the analytes (5.0 礸/L) into chlorinated surface water samples that were collected,
preserved, and stored as described in Section 8. The precision and average recovery of five
replicate extractions, conducted after 0, 7, 14 and 28 days of storage, are presented in Table 7.
13.4 EXTRACT STORAGE STABILITY STUDIES ?Extract storage stability studies were
conducted using three EtOAc extracts obtained from a chlorinated surface water, which was
fortified at 5.0 礸/L. The precision and average recovery, observed after zero, 7, 14 and 28
days of storage, are presented in Table 8.
14. POLLUTION PREVENTION
14.1 This method utilizes solid phase extraction to extract analytes from water. It requires the use
of very small volumes of organic solvent and very small quantities of pure analytes, thereby
minimizing the potential hazards to both the analyst and the environment as compared to the
use of large volumes of organic solvents in conventional liquid-liquid extractions.
14.2 For information about pollution prevention that may be applicable to laboratory operations,
consult "Less is Better: Laboratory Chemical Management for Waste Reduction" available
from the American Chemical Society's Department of Government Relations and Science
Policy, 1155 16th Street N.W., Washington, D.C., 20036 or on-line at
http://membership.acs.org/c/ccs/pub_9.htm.
15. WASTE MANAGEMENT
15.1 The analytical procedures described in this method generate relatively small amounts of waste
since only small amounts of reagents and solvents are used. The matrices of concern are
finished drinking water or source water. However, the Agency requires that laboratory waste
management practices be conducted consistent with all applicable rules and regulations, and
that laboratories protect the air, water, and land by minimizing and controlling all releases
from fume hoods and bench operations. In addition, compliance is required with any sewage
discharge permits and regulations, particularly the hazardous waste identification rules and
land disposal restrictions.
527-28
16. REFERENCES
1. Winslow, S. D.; Pepich, B. V.; Martin, J. J.; Hallberg, G. R.; Munch D. J.; Frebis, C. P.; Hedrick, E.
J.; Krop, R. A. Statistical Procedures for Determination and Verification of Minimum Reporting
Levels for Drinking Water Methods. Environ. Sci. Technol. 2006; 40, 281-288.
2. Glaser, J.A.; Foerst, D.L.; McKee, G.D.; Quave, S.A.; Budde, W.L. Trace Analyses for
Wastewaters. Environ. Sci. Technol. 1981; 15, 1426-1435.
3. Carcinogens - Working With Carcinogens, Department of Health, Education, and Welfare, Public
Health Service, Center for Disease Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, Aug. 1977.
4. Occupational Exposures to Hazardous Chemicals in Laboratories; 29 CFR 1910.1450, Occupational
Safety and Health Administration, 1990.
5. Safety in Academic Chemistry Laboratories; American Chemical Society Publication, Committee on
Chemical Safety, 7th Edition: Washington, D.C., 2003.
6. Standard Practice for Sampling Water from Closed Conduits; ASTM Annual Book of Standards,
Section 11, Volume 11.01, D3370-08; American Society for Testing and Materials: Philadelphia,
PA, 2008.
7. Erney, D.R.; Gillespie, A.M.; Gilvydis, D.M.; Poole, C.F. Explanation of the Matrix-Induced
Chromatographic Response Enhancement of Organophosphorous Pesticides During Open Tubular
Column Gas Chromatography with Splitless or Hot On-Column Injection and Flame Photometric
Detection. J. Chromatogr. 1993; 638, 57-63.
8. Mol, H.G.J.; Althuizen, M.; Janssen, H.; Cramers, C.A.; Brinkman, U.A.Th. Environmental
Applications of Large Volume Injection in Capillary GC Using PTV Injectors. J. High Resol.
Chromatogr. 1996; 19, 69-79.
9. Erney, D.R.; Pawlowski, T.M.; Poole, C.F. Matrix Induced Peak Enhancement of Pesticides in Gas
Chromatography. J. High Resol. Chromatogr. 1997; 20, 375-378.
10. Hajslova, J.; Holadova, K.; Kocourek, V.; Poustka, J.; Godula, M.; Cuhra, P.; Kempny, M. Matrix
Induced Effects: A Critical Point in the Gas Chromatographic Analysis of Pesticide Residues. J.
Chromatogr. 1998; 800, 283-295.
11. Wylie, P. and Uchiyama, M. Improved Gas Chromatographic Analysis of Organophosphorous
Pesticides with Pulsed Splitless Injection. J. AOAC International. 1996; 79, 2, 571-577.
527-29
17. TABLES, DIAGRAMS, FLOWCHARTS AND VALIDATION DATA
TABLE 1. ION ABUNDANCE CRITERIA FOR DECAFLUOROTRIPHENYLPHOSPHINE
(DFTPP)
Purpose of Checkpoint a
Mass Relative Abundance Criteria
(m/z)
51 10-85% of base peak Low-mass sensitivity
68 < 2% of m/z 69 Low-mass resolution
70 < 2% of m/z 69 Low-mass resolution
127 10-80% of base peak Low- to mid-mass resolution
197 < 2% of m/z 198 Mid-mass resolution
198 Base peak or >50% of m/z 442 Mid-mass resolution and sensitivity
199 5-9% of m/z 198 Mid-mass resolution and isotope ratio
275 10-60% of base peak Mid- to high-mass sensitivity
365 > 0.5 of m/z 198 Baseline threshold
441 < 150% of m/z 443 High-mass resolution
442 Base peak or >30% of m/z 198 High-mass resolution and sensitivity
443 15-24% of m/z 442 High-mass resolution and isotope ratio
a. All ions are used primarily to check the mass measuring accuracy of the mass spectrometer and data system,
and this is the most important part of the performance test. The three resolution checks, which include natural
abundance isotope ratios, constitute the next most important part of the performance test. The correct setting
of the baseline threshold, as indicated by the presence of low intensity ions, is the next most important part of
the test. Finally, the ion abundance ranges are designed to encourage some standardization to fragmentation
patterns.
527-30
TABLE 2. RETENTION TIMES (RT), SUGGESTED QUANTITATION IONS AND
SUGGESTED INTERNAL STANDARD (IS) REFERENCE
Peak No. (Fig. 1)
Analyte RT Quan. Ion IS No.
(min)
1,3-Dimethyl-2-Nitrobenzene (SUR) 1 4.86 134 1
Acenaphthene-d10 (IS#1) 2 6.99 164 -
Dimethoate 3 8.64 87 1
Atrazine 4 8.81 200 1
Propazine 5 8.87 229 1
Phenanthrene-d10 (IS#2) 6 9.33 188 -
Vinclozolin 7 10.30 212 2
Prometryn 8 10.63 241 2
Bromacil 9 11.08 205 2
Malathion 10 11.21 173 2
Chlorpyrifos 11 11.40 197 2
Thiobencarb 12 11.46 100 2
Parathion 13 11.63 291 2
Terbufos-Sulfone 14 12.53 153 2
Oxychlordane 15 12.64 185 2
Esbiol 16 12.78 123 2
Nitrophen 17 15.37 283 2
Kepone 18 16.71 272 2
Norflurazon 19 17.05 145 2
Hexazinone 20 17.59 171 2
Triphenylphosphate (SUR) 21 18.16 326 2
Chrysene-d12 (IS#3) 22 19.26 240 -
Bifenthrin 23 19.48 181 3
a
24 20.24 326 3
2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47)
Mirex 25 21.40 272 3
a
26 23.64 403.8 3
2,2',4,4',6-Pentabromodiphenyl Ether (BDE-100)
a
27 24.77 403.8 3
2,2',4,4',5-Pentabromodiphenyl Ether (BDE-99)
Perylene-d12 (SUR) 28 26.27 264 3
Fenvalerate 29 27.56 167 3
Hexabromobiphenyl 30 27.58 308 3
Esfenvalerate 31 28.07 167 3
a
32 29.07 643.5 3
2,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153)
a. The degree of bromination of these molecules and the relative abundance of the bromine isotopes can yield
m/z values for parent and/or daughter ions that require setting fractional m/z values for ion extraction routines.
Failure to account for this can lead to poor precision.
527-31
TABLE 3. LCMRLs AND DLs IN REAGENT WATER FOR SDVB DISK PROCEDURES
b
Analyte Spiking Conc. DL LCMRL S/N @
a
(礸/L) (礸/L)
(礸/L) LCMRL
Dimethoate 0.10 0.025 0.36 7
Atrazine 0.10 0.036 0.16 12
Propazine 0.10 0.039 0.18 15
Vinclozolin 0.20 0.084 0.29 15
Prometryn 0.10 0.028 0.20 17
Bromacil 0.20 0.093 0.45 9
Malathion 0.20 0.057 0.51 12
Chlorpyrifos 0.10 0.026 0.12 11
Thiobencarb 0.20 0.038 0.13 10
Parathion 0.20 0.062 0.29 5
Terbufos-Sulfone 0.10 0.041 0.27 18
Oxychlordane 0.35 0.110 0.27 9
Esbiol 0.10 0.041 0.31 15
Nitrophen 0.20 0.071 0.51 13
Kepone 0.20 0.076 0.35 5
Norflurazon 0.20 0.076 0.53 14
Hexazinone 0.10 0.046 0.41 22
Bifenthrin 0.20 0.040 0.21 21
2,2',4,4'-Tetrabromodiphenyl Ether
0.10 0.028 0.18 6
(BDE-47)
Mirex 0.10 0.022 0.31 13
2,2',4,4',6-Pentabromodiphenyl Ether
0.35 0.051 0.29 6
(BDE-100)
2,2',4,4',5-Pentabromodiphenyl Ether
0.20 0.097 0.39 6
(BDE-99)
Hexabromobiphenyl 0.37 0.110 0.44 10
Fenvalerate 0.35 0.079 0.67 16
Esfenvalerate 0.20 0.062 0.48 12
2,2',4,4',5,5'-Hexabromodiphenyl Ether
0.20 0.140 0.40 11
(BDE-153)
a. Spiking concentration used to determine DL.
b. S/N = signal to noise ratio.
527-32
TABLE 4. PRECISION AND ACCURACY DATA FOR METHOD ANALYTES FORTIFIED
AT 1.0 AND 5.0 礸/L IN REAGENT WATER EXTRACTED WITH SDVB DISKS
Concentration = 1.0 Concentration = 5.0
礸/L, n=5 礸/L, n=5
Mean % Mean %
%RSD %RSD
Analyte Recovery Recovery
Dimethoate 114 5.3 85.8 4.5
Atrazine 109 13 85.8 8.7
Propazine 94.6 9.1 82.3 9.1
Vinclozolin 116 5.0 93.8 6.0
Prometryn 106 4.1 85.6 5.6
Bromacil 127 5.1 103 5.7
Malathion 107 2.1 86.4 4.5
Chlorpyrifos 98.0 3.3 84.6 5.4
Thiobencarb 102 1.8 87.0 4.7
Parathion 107 4.1 87.4 5.1
Terbufos-Sulfone 111 4.2 93.2 4.3
Oxychlordane 106 3.9 84.0 6.0
Esbiol 119 4.1 97.2 5.2
Nitrophen 116 3.5 100 4.6
Kepone 103 4.3 82.8 4.3
Norflurazon 134 1.9 106 5.8
Hexazinone 120 7.0 94.1 6.8
Bifenthrin 102 1.8 78.7 4.3
2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) 93.0 5.0 81.3 4.1
Mirex 93.0 3.4 75.4 4.7
2,2',4,4',6-Pentabromodiphenyl Ether (BDE-100) 93.4 8.1 83.6 3.9
2,2',4,4',5-Pentabromodiphenyl Ether (BDE-99) 98.4 8.6 86.8 5.4
a
102 5.8 82.0 3.6
Hexabromobiphenyl
Fenvalerate 120 3.6 95.6 4.4
Esfenvalerate 111 3.4 86.3 4.8
2,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153) 96.4 10 85.4 9.3
1,3-Dimethyl-2-Nitrobenzene (SUR) 92.6 3.2 87.7 9.1
Triphenylphosphate (SUR) 88.0 2.0 88.4 4.8
Perylene-d12 (SUR) 84.4 4.8 78.5 5.6
a. Precision and accuracy determinations were obtained by using a technical mixture of hexabromobiphenyl
(Firemaster BP-6). Actual spiked concentrations for the isomer 2,2',4,4',5,5'-hexabromobiphenyl are 0.74
礸/L and 3.70 礸/L, respectively.
527-33
TABLE 5. PRECISION AND ACCURACY DATA FOR METHOD ANALYTES FORTIFIED
AT 1.0 AND 5.0 礸/L IN SURFACE WATER EXTRACTED WITH SDVB DISKS
Concentration = 1.0 Concentration = 5.0
礸/L, n=5 礸/L, n=5
Mean % Mean %
%RSD %RSD
Analyte Recovery Recovery
Dimethoate 112 2.7 89.3 2.6
Atrazine 106 4.5 102 2.9
Propazine 92.4 6.3 89.8 4.1
Vinclozolin 115 4.7 103 6.0
Prometryn 101 2.9 91.0 4.9
Bromacil 119 2.1 104 3.2
Malathion 106 2.5 95.4 4.0
Chlorpyrifos 94.6 2.4 91.1 4.8
Thiobencarb 96.0 2.7 95.0 4.5
Parathion 105 2.1 93.8 4.7
Terbufos-Sulfone 107 1.6 97.3 4.6
Oxychlordane 94.4 4.9 90.6 3.4
Esbiol 114 2.6 104 4.8
Nitrophen 111 2.7 98.8 3.7
Kepone 91.4 5.0 88.1 4.0
Norflurazon 122 4.8 105 3.2
Hexazinone 120 2.2 101 3.1
Bifenthrin 96.8 2.4 89.8 5.1
2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) 92.6 6.3 88.8 2.9
Mirex 79.6 5.4 86.6 5.6
2,2',4,4',6-Pentabromodiphenyl Ether (BDE-100) 95.8 5.1 91.0 1.8
2,2',4,4',5-Pentabromodiphenyl Ether (BDE-99) 108 4.6 93.4 2.7
a
102 9.2 95.2 2.5
Hexabromobiphenyl
Fenvalerate 124 3.4 105 3.9
Esfenvalerate 113 2.9 97.3 3.3
2,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153) 108 6.7 91.3 5.3
1,3-Dimethyl-2-Nitrobenzene (SUR) 79.8 5.2 96.5 14
Triphenylphosphate (SUR) 82.8 3.6 97.7 4.2
Perylene-d12 (SUR) 83.2 3.0 92.6 4.2
a. Precision and accuracy determinations were obtained by using a technical mixture of hexabromobiphenyl
(Firemaster BP-6). Actual spiked concentrations for the isomer 2,2',4,4',5,5'-hexabromobiphenyl are 0.74
礸/L and 3.70 礸/L, respectively.
527-34
TABLE 6. PRECISION AND ACCURACY DATA FOR METHOD ANALYTES FORTIFIED
AT 1.0 AND 5.0 礸/L IN GROUND WATER EXTRACTED WITH SDVB DISKS
Concentration = 1.0 Concentration = 5.0
礸/L, n=5 礸/L, n=4
Mean % Mean %
%RSD %RSD
Analyte Recovery Recovery
Dimethoate 114 7.1 78.0 4.3
Atrazine 120 7.2 89.7 9.6
Propazine 97.8 9.8 82.5 9.5
Vinclozolin 116 6.0 95.8 8.9
Prometryn 102 8.2 84.5 9.7
Bromacil 128 7.3 93.3 9.5
Malathion 106 6.1 85.3 10
Chlorpyrifos 100 3.5 84.8 10
Thiobencarb 100 6.4 85.8 9.6
Parathion 103 4.2 86.6 9.8
Terbufos-Sulfone 110 8.1 87.3 11
Oxychlordane 102 12 85.8 10
Esbiol 109 8.3 94.8 8.6
Nitrophen 109 6.3 89.2 8.4
Kepone 84.4 6.7 75.0 7.4
Norflurazon 116 6.4 94.5 7.8
Hexazinone 114 7.7 92.9 7.5
Bifenthrin 98.2 6.0 76.7 11
2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) 86.6 6.8 78.0 5.6
Mirex 90.4 8.0 72.7 12
2,2',4,4',6-Pentabromodiphenyl Ether (BDE-100) 86.4 5.8 79.8 3.8
2,2',4,4',5-Pentabromodiphenyl Ether (BDE-99) 86.8 8.9 82.7 4.2
a
87.8 5.1 79.5 6.1
Hexabromobiphenyl
Fenvalerate 116 8.4 93.7 7.2
Esfenvalerate 111 8.2 87.7 9.4
2,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153) 99.8 9.8 82.7 4.6
1,3-Dimethyl-2-Nitrobenzene (SUR) 95.4 5.8 85.5 12
Triphenylphosphate (SUR) 89.8 4.6 86.1 9.6
Perylene-d12 (SUR) 85.8 3.3 82.9 8.5
a. Precision and accuracy determinations were obtained by using a technical mixture of hexabromobiphenyl
(Firemaster BP-6). Actual spiked concentrations for the isomer 2,2',4,4',5,5'-hexabromobiphenyl are 0.74
礸/L and 3.70 礸/L, respectively.
527-35
TABLE 7. AQUEOUS SAMPLE HOLDING TIME DATA FOR SAMPLES FROM CHLORINATED SURFACE WATER, FORTIFIED
a
WITH METHOD ANALYTES AT 5 礸/L AND PRESERVED ACCORDING TO SECTION 8
Analyte Day 0 Day 0 Day 7 Day 7 Day 14 Day 14 Day 21 Day 21 Day 28 Day 28
% Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD
Dimethoate 82.5 6.4 95.8 2.3 88.0 6.7 80.9 6.2 87.1 9.6
Atrazine 78.6 10 78.9 0.1 72.7 14 72.6 5.9 75.5 9.5
Propazine 79.1 11 78.7 1.2 74.3 14 72.1 6.7 72.1 9.9
Vinclozolin 86.3 12 83.1 2.8 81.7 16 80.6 5.9 78.9 7.2
Prometryn 84.7 11 85.5 2.4 84.7 10 82.9 4.8 85.3 7.5
Bromacil 96.8 14 98.5 2.0 101 8.6 95.4 5.5 109 7.3
Malathion 86.3 12 86.1 3.7 85.2 10 79.6 4.9 85.5 7.8
Chlorpyrifos 84.9 8.9 81.8 1.4 83.5 10 74.9 4.8 75.3 6.8
Thiobencarb 87.1 11 90.4 3.8 86.9 13 85.1 4.9 86.5 6.9
Parathion 89.6 9.8 87.3 1.3 88.1 12 85.4 3.7 92.7 6.4
Terbufos-Sulfone 86.9 12 89.5 2.5 88.7 14 84.3 5.1 86.8 7.1
Oxychlordane 80.7 9.0 78.9 5.4 77.6 12 75.7 5.6 68.8 7.0
Esbiol 92.7 9.6 93.1 3.8 91.3 14 89.8 4.1 88.9 7.3
Nitrophen 97.7 8.5 94.8 4.0 96.4 9.0 90.8 8.0 96.3 6.2
Kepone 68.4 10 70.8 2.8 71.7 15 74.9 1.9 75.7 9.6
Norflurazon 103 11 102 2.6 101 12 99.4 4.2 114 7.0
Hexazinone 98.5 5.8 92.8 2.1 116 7.9 110 4.0 130 3.7
Bifenthrin 89.5 2.5 80.9 8.1 87.6 4.8 78.7 5.8 72.7 5.2
2,2',4,4'-Tetrabromodiphenyl Ether
87.2 1.1 75.6 9.0 87.2 6.4 76.5 4.2 71.0 6.8
(BDE-47)
Mirex 83.8 2.5 75.7 9.7 84.3 5.5 71.8 6.2 64.5 6.7
2,2',4,4',6-Pentabromodiphenyl
87.3 4.4 83.5 11 88.9 4.2 78.6 2.9 74.5 2.6
Ether (BDE-100)
2,2',4,4',5-Pentabromodiphenyl
92.6 3.1 77.7 8.2 94.1 6.1 84.5 6.9 78.9 4.8
Ether (BDE-99)
527-36
TABLE 7. AQUEOUS SAMPLE HOLDING TIME DATA FOR SAMPLES FROM CHLORINATED SURFACE WATER, FORTIFIED
WITH METHOD ANALYTES AT 5 礸/L AND PRESERVED ACCORDING TO SECTION 8 (CONTINUED)
Analyte Day 0 Day 0 Day 7 Day 7 Day 14 Day 14 Day 21 Day 21 Day 28 Day 28
% Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD
Hexabromobiphenyl 92.5 4.4 76.9 11 92.4 5.2 80.5 10.6 74.9 3.7
Fenvalerate 116 2.9 97.7 18 104 5.1 106 14 97.3 6.9
Esfenvalerate 103 3.3 84.6 12 102 5.1 96.9 12 92.4 2.5
2,2',4,4',5,5'-Hexabromodiphenyl
89.8 4.6 79.2 28 93.3 6.1 84.9 5.1 87.5 10
Ether (BDE-153)
1,3-Dimethyl-2-Nitrobenzene (SUR) 74.9 7.7 81.9 5.1 80.3 12 79.3 8.1 82.4 9.7
Triphenylphosphate (SUR) 79.9 9.8 84.2 2.4 87.7 16 90.8 4.8 96.6 7.5
Perylene-d12 (SUR) 96.9 8.3 89.5 3.9 92.1 5.2 99.1 4.5 104 4.3
a. Average recovery and precision are based on five replicate samples extracted at each time point.
527-37
TABLE 8. EXTRACT HOLDING TIME DATA FOR SAMPLES FROM CHLORINATED SURFACE WATER, FORTIFIED WITH
a
METHOD ANALYTES AT 5 礸/L AND PRESERVED ACCORDING TO SECTION 8
Analyte Day 0 Day 0 Day 7 Day 7 Day 14 Day 14 Day 21 Day 21 Day 28 Day 28
% Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD
Dimethoate 82.5 6.4 87.5 8.8 84.1 11 86.9 9.4 94.2 4.9
Atrazine 78.6 10 78.1 13 76.3 14 78.9 14 86.1 12
Propazine 79.1 11 76.0 11 77.1 15 78.7 14 83.3 13
Vinclozolin 86.3 12 85.3 13 88.8 14 90.3 12 87.5 11
Prometryn 84.7 11 89.6 0.0 86.1 12 87.1 13 87.0 12
Bromacil 96.8 14 104 0.7 98.6 12 102 13 112 13
Malathion 86.3 12 89.7 3.3 87.5 14 84.4 12 89.4 11
Chlorpyrifos 84.9 8.9 87.0 3.3 87.4 12 83.7 11 84.4 7.4
Thiobencarb 87.1 11 92.2 2.5 88.7 12 90.4 10 88.6 10
Parathion 89.6 9.8 90.4 0.3 89.7 12 90.7 14 96.2 12
Terbufos-Sulfone 86.9 12 94.4 2.1 90.9 14 90.1 13 90.5 12
Oxychlordane 80.7 9.0 81.8 4.1 83.7 3.9 82.3 4.3 87.6 5.4
Esbiol 92.7 9.6 94.2 2.7 92.8 12 96.0 11 92.9 9.0
Nitrophen 97.7 8.5 95.8 5.3 98.2 10 97.9 13 100 8.8
Kepone 68.4 10 73.7 0.2 75.3 11 74.9 12 75.5 11
Norflurazon 103 11 105 1.8 106 10 117 19 115 12
Hexazinone 98.5 5.8 98.9 2.1 122 8.4 123 11 135 13
Bifenthrin 89.5 2.5 88.9 2.1 84.5 2.8 86.3 2.2 87.6 5.2
2,2',4,4'-Tetrabromodiphenyl Ether
87.2 1.1 84.2 2.3 86.7 3.2 81.1 1.4 85.7 1.6
(BDE-47)
Mirex 83.8 2.5 86.1 3.0 81.3 2.2 80.5 5.2 82.5 6.9
2,2',4,4',6-Pentabromodiphenyl
87.3 4.4 92.2 5.2 87.5 1.0 85.1 2.4 87.0 1.7
Ether (BDE-100
2,2',4,4',5-Pentabromodiphenyl
92.6 3.1 90.0 6.4 88.2 0.8 95.2 3.1 95.1 3.9
Ether (BDE-99)
527-38
TABLE 8. EXTRACT HOLDING TIME DATA FOR SAMPLES FROM CHLORINATED SURFACE WATER, FORTIFIED WITH
METHOD ANALYTES AT 5 礸/L AND PRESERVED ACCORDING TO SECTION 8. (CONTINUED)
Analyte Day 0 Day 0 Day 7 Day 7 Day 14 Day 14 Day 21 Day 21 Day 28 Day 28
% Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD % Rec. % RSD
Hexabromobiphenyl 92.5 4.4 85.1 8.7 89.0 0.4 89.7 1.2 94.5 4.2
Fenvalerate 116 2.9 107 2.4 101 3.9 120 8.4 119 8.5
Esfenvalerate 103 3.3 94.7 4.4 102 1.9 110 5.4 110 5.9
2,2',4,4',5,5'-Hexabromodiphenyl
89.8 4.6 90.5 9.1 84.9 5.4 92.3 3.3 104 6.0
Ether (BDE-153)
1,3-Dimethyl-2-Nitrobenzene (SUR) 74.9 7.7 75.1 10 76.1 9.3 77.6 13 79.9 11
Triphenylphosphate (SUR) 79.9 9.8 90.1 3.9 88.5 12 92.9 11 94.4 13
Perylene-d12 (SUR) 96.9 8.3 92.9 3.4 89.0 3.7 98.5 12 107 7.4
a. % Recovery and % RSD calculated based on triplicate injections of a single sample extract that was split into enough vials to permit a new vial to be used on
each day of the holding time study.
527-39
TABLE 9. INITIAL DEMONSTRATION OF CAPABILITY QUALITY CONTROL
REQUIREMENTS
Method
Requirement Specification and Frequency Acceptance Criteria
Reference
Demonstrate that all method
analytes are below 1/3 the
Minimum Reporting Limit
Initial
(MRL) or lowest calibration
Section
Analyze LRB prior to any other
Demonstration of
standard, and that possible
9.2.1
IDC steps.
Low System
interferences from extraction
Background
media do not prevent the
identification and quantification
of method analytes.
Fortify, extract and analyze 7
replicates at the proposed MRL
concentration. Calculate the mean
Upper PIR 150%
MRL
Section
and the Half Range (HR). Confirm
Confirmation
9.2.4
that the upper and lower limits for
Lower PIR 50%
the Prediction Interval of Result
(Upper PIR, and Lower PIR, Sect.
9.2.4.2) meet the recovery criteria.
Analyze 4 to 7 replicate LFBs
Initial
Section
%RSD must be 20%
fortified near the midrange
Demonstration of
9.2.2
concentration.
Precision
Initial
Section
Mean recovery 30% of true
Calculate mean recovery for
Demonstration of
9.2.3
replicate LFBs (Sect. 9.2.2). value
Accuracy
527-40
TABLE 10. ONGOING QUALITY CONTROL REQUIREMENTS (SUMMARY)
Method
Requirement Specification and Frequency Acceptance Criteria
Reference
Section
Analyze DFTPP to verify MS tune each time the
10.2.1 MS Tune Check Acceptance criteria are given in Table 1
instrument is calibrated.
When each calibration standard is calculated as an unknown
Use internal standard calibration technique to generate
using the calibration curve, the result should be 70 to 130% of
Section an average RRF, first order or second order calibration
Initial Calibration
the true value for all levels except the lowest standard, which
10.2 curve. Use at least 5 standard concentrations. Check
should be 50 to 150% of the true value.
the calibration curve as described in Sect. 10.2.6.
Demonstrate that all method analytes are below 1/3 the MRL,
and confirm that possible interferences do not prevent
Section Laboratory Reagent
One LRB is required with each extraction batch. quantification of method analytes. Results for analytes detected
9.3.1 Blank (LRB)
in the LRB are invalid for all analyses within the subject
Analysis Batch.
Verify initial calibration by analyzing a CCC at the
beginning of each Analysis Batch prior to analyzing
samples, after every 10 samples, and after the last
Continuing
sample.
Section
Calibration Check
10.3
(CCC)
50% of true value
Low CCC ?at or below the MRL concentration
30% of true value
Mid CCC ?near midpoint in initial calibration curve
30% of true value
High CCC ?near the highest calibration standard
Results of LFB analyses at medium and high fortifications must
One LFB is required for each extraction batch. Rotate
Section Laboratory Fortified be 70 to 130% of the true value for each analyte and surrogate.
the fortified concentrations between low, medium, and
9.3.3 Blank (LFB) Results of the low-level LFB (less than or equal to two times
high amounts.
the MRL) must be 50 to 150% of the true value.
Peak area counts for all ISs in LFBs, LRBs, and sample extracts
Acenaphthene-d10 (IS#1) phenanthrene-d10 (IS#2), and
must be within 50% of the average peak area calculated
chrysene-d12 (IS#3), are added to all standards and
Section
during the initial calibration and 30% from the most recent
sample extracts. Compare IS areas to the average IS
Internal Standard (IS)
9.3.5
area in the initial calibration and in the most recent CCC. If ISs do not meet these criteria, corresponding analyte
CCC. results are invalid.
Surrogate standards, 1,3-dimethyl-2-nitrobenzene,
Surrogate recovery must be 70 to 130% of the true value. If a
triphenylphosphate, and perylene-d12 are added to all
Section
Surrogate Standards surrogate fails this criterion, report all results for the sample as
9.3.6 calibration standards and samples, including QC
"suspect/surrogate recovery."
samples. Calculate surrogate recoveries.
527-41
TABLE 10. ONGOING QUALITY CONTROL REQUIREMENTS (CONTINUED)
Analyte recoveries for the LFSMD or FD should be < 30% at
Analyze one LFSM per extraction batch fortified with
Laboratory Fortified
Section method analytes at a concentration close to but greater mid and high levels of fortification and < 50% at concentrations
Sample Matrix
9.3.7 than the native concentration. Calculate LFSM less than or equal to two times the MRL. A matrix effect is
(LFSM)
recoveries. indicated for analytes that fail these criteria.
Laboratory Fortified
Extract and analyze at least one FD or LFSMD with
RPDs for the LFSMD or FD should be < 30% at mid and high
Sample Matrix
each extraction batch. A LFSMD may be substituted for
Section
levels of fortification and < 50% at concentrations less than or
Duplicate (LFSMD)
a FD when the frequency of detects are low. Calculate
9.3.8
or Field Duplicates equal to two times the MRL.
RPDs.
(FD)
Section Quality Control
Analyze a QCS during the IDC and at least quarterly. Results must be 70 to 130% of the expected value.
9.3.9 Sample (QCS)
Sample results are valid only if samples are extracted within
Section 8.4 Sample holding time 14 days with appropriate preservation and storage
sample hold time.
Sample results are valid only if extracts are analyzed within
Section 8.4 Extract holding time 28 days with appropriate preservation and storage
extract hold time.
527-42
FIGURE 1. EXAMPLE CHROMATOGRAM FOR REAGENT WATER FORTIFIED WITH METHOD 527 ANALYTES AT 5 礸/L
(NUMBERED PEAKS ARE IDENTIFIED IN TABLE 2).
1
2
6
23
5
11 16
7 10
4 8 12 15
21
14 25 31
13 22
3 20
17 2 9 ,3 0
19
9 24
26 28
27
32
18
6 8 10 12 14 16 18 20 22 24 26 28 30 32
T im e (M in u te s)
527-43
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