ASTM D6160-21

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6160 − 98 (Reapproved 2017) D6160 − 21
Standard Test Method for
Determination of Polychlorinated Biphenyls (PCBs) in Waste
Materials by Gas Chromatography
This standard is issued under the fixed designation D6160; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method covers a two-tiered analytical approach to PCB screening and quantitation of liquid and solid wastes, such
as oils, sludges, aqueous solutions, and other waste matrices.
1.2 Tier I is designed to screen samples rapidly for the presence of PCBs.
1.3 Tier II is used to determine the concentration of PCBs, typically in the range of from 2 mg ⁄kg to 50 mg ⁄kg. PCB
concentrations greater than 50 mg/kg are determined through analysis of sample dilutions.
1.4 This is a pattern recognition approach, which does not take into account individual congeners that might occur, such as in
reaction by-products. This test method describes the use of Aroclors 1016, 1221, 1232, 1242, 1248, 1254, 1260, 1262, and 1268,
as reference standards, but others could also be included. Aroclors 1016 and 1242 have similar capillary gas chromatography (GC)
patterns. Interferences or weathering are especially problematic with Aroclors 1016, 1232, and 1242 and may make distinction
between the three difficult.
1.5 This test method provides sample clean up and instrumental conditions necessary for the determination of Aroclors. Gas
chromatography (GC) using capillary column separation technique and electron capture detector (ECD) are described. Other
detectors, such as atomic emission detector (AED) and mass spectrometry (MS), may be used if sufficient performance (for
example, sensitivity) is demonstrated. Further details about the use of GC and ECD are provided in Practices E355, E697, and
E1510.
1.6 Quantitative results are reported on the dry weights of waste samples.
1.7 Quantification limits will vary depending on the type of waste stream being analyzed.
1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.04.0L on Gas Chromatography Methods.
Current edition approved Oct. 1, 2017Dec. 1, 2021. Published November 2017December 2021. Originally approved in 1997. Last previous edition approved in 20132017
as D6160 – 98 (2013).(2017). DOI: 10.1520/D6160-98R17.10.1520/D6160-21.
This test method is based largely on EPA 8080 (and the proposed modification for the use of capillary columns, EPA 8081) and EPA Report 600/4–81–045 by Bellar,
T. and J. Lichtenberg, reported in 1981. The report is titled, “The Determination of Polychlorinated Biphenyls in Transformer Fluid and Waste Oils,” and provides significant
support to the protocol in this standard.
Aroclor Standards may be purchased as 1000 μg/mL in isooctane. Aroclor is a registered trademark of the Monsanto Company, 800 N. Lindbergh Blvd., St. Louis, MO
63167.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6160 − 21
1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.10 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D4059 Test Method for Analysis of Polychlorinated Biphenyls in Insulating Liquids by Gas Chromatography
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
E203 Test Method for Water Using Volumetric Karl Fischer Titration
E288 Specification for Laboratory Glass Volumetric Flasks
E355 Practice for Gas Chromatography Terms and Relationships
E697 Practice for Use of Electron-Capture Detectors in Gas Chromatography
E969 Specification for Glass Volumetric (Transfer) Pipets
E1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs
2.2 U.S. EPA Standards:
Method 608 Organochlorine Pesticides and PCBs
Method 680 Determination of Pesticides and PCBs in Water and Soil/Sediment by Gas Chromatography/Mass Spectrometry
Method 3620 Florisil Column Clean-Up
Method 3630 Silica Gel Clean-Up
Method 3660 Sulfur Clean-Up
Method 8082 Determination of PCB in Water and Soil/Sediment by Gas Chromatography: Capillary Column Technique
3. Terminology
3.1 Definitions of Terms Specific to This Standard:Definitions:
3.1.1 This test method makes reference to common gas chromatographic procedures, terms, and relationships. Detailed definitions
of these can be found in Practice E355 and Terminology D4175. In addition, definition of terms specific to this standard include:
3.1.2 Aroclors, n—commercial mixtures of polychlorinated biphenyl congeners marketed and trademarked by Monsanto prior to
1977.
3.1.2.1 Discussion—
Specific Aroclors are usually designated by a four-digit number, with the first two digits usually designating the number of carbon
atoms and the last two digits providing the chlorine content (for example, Aroclor 1260 is 60 % (weight) chlorine).
3.1.3 congeners, n—compounds related by structural similarities.
3.1.3.1 Discussion—
All polychlorinated biphenyls (PCBs) share the same C structure and vary only by the number and position of the chlorine atoms
attached to the aromatic rings.
3.1.4 continuing calibration standard (CCS)—a known blend or one or more Aroclors at a fixed concentration that is injected into
the gas chromatograph to demonstrate the validity of the calibration.
3.1.5 dry weight, n—concentration of PCBs after factoring out the water content.
3.1.5.1 Discussion—
This correction assumes that all PCBs originated from nonaqueous sources and any water present has been added subsequently,
diluting the original concentration. This correction can be described using the formula:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
EPA Report 600/4/82–057, Environmental Monitoring and Support Laboratory, Cincinnati, OH.
Alford-Stevens, Ann, et al, Physical and Chemical Methods Branch, Environmental Monitoring and Support Laboratory Office of Research and Development, USEPA,
Cincinnati, OH.
U.S. EPA, “Test Methods for Evaluating Solid Waste,” Physical/Chemical Methods, SW-846.
D6160 − 21
Aroclor mg/Kg wet
~ ! ~ !
Aroclor ~mg/Kg! ~dry!5 (1)
~100 2 % water!/100
3.1.6 instrument performance standard (IPS), n—a known low level of an Aroclor in a clean solvent used as a comparator to
determine which qualitative (screening) results are of sufficient magnitude to require quantitative analyses.
3.1.7 surrogate, n—compound or compounds that are similar to analytes of interest in chemical composition, extraction, and
chromatography, but that are not normally found at significant levels in the matrices of interest.
3.1.7.1 Discussion—
Surrogates may be spiked into blanks, standards, samples, or matrix spikes prior to analysis to allow a determination of a
quantitative recovery rate. Surrogates are also used to document matrix effects and method control.
3.1.8 waste material, n—any matter, within the scope of this test method, that is in the process of being recycled or disposed.
4. Summary of Test Method
4.1 The sample is extracted with solvent and the extract is treated to remove interfering substances, if needed. The sample extract
is injected into a gas chromatograph. The components are separated as they pass through the capillary column and polychlorinated
biphenyl compounds, if present, are detected by an ECD.
NOTE 1—Portions of this test method are similar to EPA Methods 608, 680, and 8082.
4.2 For screening (Tier I), instrument performance is monitored by a 2 μL injection of a standard containing Aroclors 1016 and
1260. For low level work (1 ppm) the instrument is checked with a standard concentration of 0.01 μg ⁄mL (each) and for higher
level work (10 ppm), the instrument is checked with a 0.1 μg ⁄mL standard.
4.3 Identification involves a pattern comparison of the chromatograms of an unknown sample with that of a standard obtained
under identical instrumental conditions.
4.4 When quantification is required (Tier II), an external standards method (ESTD) is used. The quantitation technique typically
requires a comparison of five peaks (minimum of three) between the chromatograms of an unknown sample and that of standard
Aroclor obtained under identical conditions. Quantitation of either Aroclors 1016 or 1260 is performed using a five-point
calibration of a mixed Aroclor standard containing Aroclors 1016 and 1260. All remaining Aroclors are quantitated from single
point calibrations. Calibration is verified daily by comparison of results obtained for analysis of the midpoint calibration standard
of Aroclor 1016 and 1260 to the five-point calibration curve. (See Appendix X1 for an example chromatogram and calibration
table.)
5. Significance and Use
5.1 This test method provides sufficient PCB data for many regulatory requirements. While the most common regulatory level is
50 ppm (dry weight corrected), lower limits are used in some locations. Since sensitivities will vary for different types of samples,
one shall demonstrate a sufficient method detection limit for the matrix of interest.
5.2 This test method differs from Test Method D4059 in that it provides for more sample clean-up options, utilizes a capillary
column for better pattern recognition and interference discrimination, and includes both a qualitative screening and a quantitative
results option.
6. Interferences
6.1 The ECD has selective sensitivity to alkyl halides, conjugated carbonyls, nitrogen compounds, organometallics, and sulfur.
Therefore, the chromatogram obtained for each sample shall be carefully compared to chromatograms of standards to allow proper
interpretation.
6.2 Solvents, reagents, glassware, and other sample processing hardware may yield artifacts or interferences, or both, to standard
analysis. All these materials shall be demonstrated to be free from interferences under the conditions of analysis by analyzing
method blanks.
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6.3 Interferences from phthalate esters may pose a major problem in Aroclor determinations when using ECD. Phthalates
generally appear in the chromatogram as broad late eluting peaks. Since phthalates are commonly used as plasticizers and are easily
extracted from plastic, all contact of samples and extracts with plastic should be avoided.
6.4 While general clean-up techniques are provided as part of this test method, some samples may require additional clean-up
beyond the scope of this test method before proper instrumental analysis may be performed.
7. Apparatus
7.1 Gas Chromatograph, a temperature programmable gas chromatograph suitable for splitless injections; equipped with an ECD.
7.2 Data System, a data system capable of measuring peak areas.
7.3 Regulator (Make-up Gas)—N or Ar:Methane (95:5); two stage regulator rated at 20 MPa (3000 psi) inlet and 35 to 860 kPa
(5 35 kPa to 860 kPa (5 psi to 125 psi) outlet.
7.4 Regulator (Carrier Gas)—H , two-stage regulator rated at 20 MPa (3000 psi) inlet and 3535 kPa to 860 kPa (5(5 psi to 125
psi) 125 psi) outlet.
7.5 Gas Purifiers, to remove moisture and particulates. Depending on the levels and types of interferences encountered, these
might involve molecular sieves (moisture), activated carbon (organics), or other commercially-available media.
7.6 Flow Meter, to measure gas flow. Typical range is from 0.5 mL ⁄min. to 50 mL ⁄min. 6 0.1 mL ⁄min.
7.7 Column, crosslinked 5 % phenyl methyl silicone, 30 m by 0.32 mm id by 0.25 μm film thickness.
7.7.1 It is possible that other columns will provide sufficient separating power, but this shall be demonstrated before use.
7.8 Analytical Balance, capable of weighing to 0.0001 g.
7.9 Volumetric Flasks, 10 mL, 50 mL, 100 mL, 200 mL, (see Specification E288) Class A with ground-glass stoppers.
7.10 Vortex Mixer:
7.11 Vials, glass, 20 mL and 40 mL capacity with TFE-fluorocarbon-lined caps.
7.12 Septum Inserts—Inserts shall be treated with a silynization reagent before use or after cleaning. (See Annex A2 for possible
procedure.) They may be purchased already treated.
7.13 Volumetric Pipette, 1 mL, 5 mL, 10 mL (see Specification E969), Class A.
7.14 Syringe, 500 μL, mechanical guide.
8. Reagents and Materials
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
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specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity
to permit its use without lessening the accuracy of the determination.
8.2 Acetone—(Warning—Extremely flammable. Vapors may cause flash fire.)
8.3 Activated Magnesium Silicate (Florisil), Pesticide residue (PR) grade (60/100 mesh); store in glass containers with ground
glass stoppers or foil lined screw caps.
8.3.1 Just before use, activate each batch at least 4 h at 130 °C in a glass container loosely covered with aluminum foil.
Alternatively, store the magnesium silicate in an oven at 130 °C. Cool the magnesium silicate in a desiccator for 30 min before
use.
8.4 Hexane—(Warning—Extremely flammable. Harmful if inhaled. May produce nerve cell damage. Vapors may cause flash
fire.)
8.5 Isooctane—(Warning—Extremely flammable. Harmful if inhaled. Vapors may cause flash fire.)
8.6 Methanol—(Warning—Flammable. Vapor harmful. May be fatal or cause blindness if swallowed or inhaled. Cannot be made
nonpoisonous.)
8.7 Silynization Reagent (for example, 5 % dimethyldichlorosilane in toluene). See Annex A2 for instructions.
8.8 Sodium Sulfate, granular, anhydrous (maintained at 130 °C for at least 24 h prior to use). Cool the sodium sulfate in a
desiccator for 30 min before use.
8.9 Sulfuric Acid (concentrated):
8.10 Acetone/Hexane, 10 % acetone/90 % hexane (v/v).
8.11 Gases, Hydrogen (zero grade; 99.995 % purity) and nitrogen (zero grade; 99.998 % purity) or argon/methane (95:5; ECD
grade).
8.11.1 Care shall be given to ensure purity of the carrier gas. For example, an in-line filter may be required.
8.12 Aroclor Standards , Aroclor 1016, 1221, 1232, 1242, 1254, 1260, 1262, 1268.
8.13 Decachlorobiphenyl (DCB) (surrogate) Optional:
8.13.1 Surrogate Stock Standard (15 μg/mL) Preparation—Accurately dilute 1.5 mL of 1000 μg ⁄mL DCB concentrate in 100 mL
volumetric flask and fill to the mark with methanol, yielding a 15 μg ⁄mL solution.
8.13.2 Surrogate Working Standard (1.5 μg ⁄mL) Preparation—Accurately dilute 10 mL of the 15 μg ⁄mL DCB stock standard in
a 100 mL volumetric flask and fill to the mark with methanol, yielding a 1.5 μg ⁄mL working DCB standard.
NOTE 2—Sample preparations will normally use 0.1 mL of this solution. The resulting concentration in the sample extract is 0.005 μg ⁄mL before any
further dilutions. The following calculations show this.
1.5 µg/mL 30.l mL 5 0.15 µg (2)
0.15 µg
5 0.005 µg/mL
~3.0 mL sample127 mL!
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not listed by the American Chemical Society, see
AnnualAnalar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial
Convention, Inc. (USPC), Rockville, MD.
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8.14 Calibration Standards:
8.14.1 Intermediate Stock Standard (50 μg ⁄mL): If high level standards (for example, commercially available standards at
2000 μg ⁄mL to 5000 μg/mL) have been purchased, prepare solutions of 50 μg ⁄mL concentration.
8.14.1.1 The surrogate calibration standard may be added (optional) to the Aroclor 1016/1260 intermediate stock standard at a
concentration of 2.5 μg ⁄mL. For preparation of the standard, add 500 μL of 50 μg ⁄mL surrogate to a 10 mL volumetric flask
containing 3.0 mL of isooctane. Add the Aroclor 1016/1260 standard (5.0 mL at 100 μg ⁄mL) to the flask. Dilute to 10 mL volume
with isooctane and mix well.
8.14.1.2 To prepare the continuing CCS, dilute 200 μL of the intermediate stock standard to 100 mL.
Volume add into Ar-1016/1260 concentration Surrogate concentration
the 100 mL flask μg/mL μg/mL
200 μL 0.10 0.005
8.14.2 Instrument Performance Standard (IPS) (Tier I–Screening)—An isooctane solution of Aroclors 1016 and 1260 is prepared
at a concentration of 0.01 μg ⁄mL (each) or 0.1 μg ⁄mL (each) (depending on whether the minimum level of interest is 2 μg ⁄mL or
20 μg ⁄mL) from the appropriate stock standard.
8.14.2.1 If the surrogate (decachlorobiphenyl, (DCB)) is used, it shall be added to the IPS to result in a concentration of
0.005 μg ⁄mL.
8.14.2.2 To prepare the IPS along with DCB, add 10 mL of Aroclor 1016/1260 at 0.1 μg ⁄mL and 0.033 mL of DCB at 15 μg ⁄mL
into 100 mL volumetric flask. Dilute to 100 mL volume with isooctane. Mix well. This yields 0.01 μg ⁄mL IPS and 0.005 μg ⁄mL
of DCB.
8.14.2.3 The following additional standards shall be run once (at 0.1 μg ⁄mL) to demonstrate the Aroclor patterns and be mixed
if preferred.
Aroclor Mix with the following:
1268 1221 or 1232 or 1242 or 1248 or 1254
1262 1221 or 1232 or 1242 or 1248
1254 1221
8.14.3 Individual Working Standards (Tier 2–Quantitation)—Working standards are typically prepared in isooctane at concen-
trations of 0.02 μg ⁄mL, 0.05 μg ⁄mL, 0.1 μg ⁄mL, 0.3 μg ⁄mL and 0.5 μg ⁄mL for Aroclors 1016 and 1260. All other Aroclors are
prepared at the mid level concentration (0.1 μg ⁄mL) for the single point calibration. An alternative calibration range may be used
as long as the criteria for linearity of the calibration range is documented.
8.14.3.1 Aroclors 1016 and 1260 shall be a mixed standard. The following additional standards shall be run once (at 0.1 μg ⁄mL)
to demonstrate the Aroclor patterns and may be mixed, if preferred.
Aroclor May be mixed with:
1268 1221 or 1232 or 1242 or 1248 or 1254
1262 1221 or 1232 or 1242 or 1248
1254 1221
8.15 Quality Control Standards:
8.15.1 Calibration Check Standard (CCS) (Tier 2–Quantitation)—This standard contains 0.1 μg ⁄mL (those who are interested in
the 20 mg ⁄Kg level with no compositing, use 0.2 μg ⁄mL each) each of Aroclors 1016 and 1260 in hexane.
8.15.1.1 The surrogate concentration, if used, is 0.005 μg ⁄mL.
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8.15.1.2 Example—To prepare the CCS along with DCB, add 20 mL of Aroclors 1016/1260 to 0.5 μg ⁄mL and 0.05 mL of DCB
at 10 μg ⁄mL into 100 mL volumetric flask. Dilute to 100 mL volume with isooctane. Mix well. This yields a 0.1 μg ⁄mL of CSS
and 0.005 μg ⁄mL of DCB.
8.15.2 Matrix Spiking Standard (Tier 2–Quantitation)—The matrix spiking standard is to contain Aroclor 1268 at a concentration
of 50 μg ⁄mL in methanol. Laboratories working at lower calibration ranges will need to dilute this (for example, to 25 μg ⁄mL).
8.16 Copper Powder, 200 mesh, 99 % min.
8.17 Silica Gel, 100 to 200 mesh.
9. Sampling
9.1 PCBs are hydrophobic compounds. Therefore, when sampling, all organic phases, including bottom sludge beneath aqueous
phases, shall be sampled. Given the possible presence of alcohols and glycols, it is typically not acceptable to sample the organic
phase only.
9.2 Headspace above stored standards and samples or extracts should be minimized such that the volume is less than 50 %.
9.3 Three mL of sample are required for each determination. No special sample preservation is required other than storage in a
closed container with minimal headspace. It is accepted practice to use borosilicate glass containers with TFE-fluorocarbon-lined
lids.
10. Preparation of Apparatus
10.1 General Gas Chromatographic Conditions—The first temperature profile (12 min run time) is used for Tier I screening
method for the presence of Aroclor. The longer second temperature profile (17 min run time) is used for Tier II to quantitate the
Aroclors present, but may also be used for Tier I, if desired.
10.1.1 Rapid Screen Capillary Column Oven Temperature Profile (Tier I, 12 min run time):
Initial value 130 °C
Initial time 2 min
Program rate 20 °C ⁄min
Final value 270 °C
Final time 3 min
Carrier gas hydrogen
Head pressure depend on DCB RT
(approximately 105 KPa (15 psi)) column
flow: 3.1 mL ⁄min-3.2 mL ⁄min
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Make-up gas nitrogen or argon: methane
Make-up gas rate approximately 65 mL ⁄min.
Splitless mode
Purge off 0 min
Purge on 1.0 min
Purge vent 2.5 mL/min
Split vent 50 mL/min
Sample injection 2.0 μL
Injector inlet system 250 °C
Detector 315 °C
10.1.2 Quantitation Capillary Column Oven Temperature Profile (Tier II, 17 min run time; may also be used for Tier I analysis:
Initial value 125 °C
Initial time 3 min
Level I
Program rate 12 °C ⁄min
Final value 270 °C
Final time 2 min
Carrier gas hydrogen
Head pressure Depend on DCB RT
(approximately, 105 KPa (15 psi))
Column flow 3.1 mL/min (approximately at 270 °C)
Make-up gas nitrogen
Make-up gas rate approximately 65 mL/min
Splitless mode
Purge off 0 min
Purge on 1.0 min
Purge rate 50 mL/min
Sample injection 2.0 μL
Injector inlet system 250 °C
Detector 315 °C
11. Calibration and Standardization
11.1 Calibration:
11.1.1 Tier 1–Screening Method—Aroclors are multi-peak chemical mixtures that have very unique identification patterns. All
Aroclors shall be run individually or in mixtures at 0.1 μg ⁄mL on each channel performing screening to produce reference patterns.
It is important to note that some of these patterns have the same constituents and that some Aroclors are quantitated using the same
peaks (such as Aroclors 1016 and 1232 or 1242). When screening for Aroclors, a visual determination is made by the following
key items:
11.1.1.1 Aroclor pattern—(a) same singlets, doublets, and triplets present in the reference chromatograms, and (b) same relative
peak heights between peaks in the sample chromatogram and the reference chromatogram.
11.1.1.2 Retention time shifts should be very consistent between the standard and the sample peaks.
11.1.1.3 All samples in which an Aroclor is detected (using Tier I) require a judgment concerning the amount. The recognized
Aroclor pattern shall be compared to the IPS (0.01 μg ⁄mL or 0.1 μg ⁄mL). If the overall level of the suspected Aroclor pattern is
equal to or greater than overall level of the IPS pattern, then Tier II analysis may be used to quantitate the sample. If multiple
Aroclors are suspected, a Tier II analysis may be run to help resolve the mixture.
11.1.1.4 Recovery control limits for the surrogate are 40 % to 150 % recovered. If the recovery is outside of these limits, see
Annex A1.
11.1.2 Tier I Calibration Check—An instrument performance standard (IPS) at 0.01 μg ⁄mL of Aroclor 1016 and 1260 is used to
check the instrument sensitivity once a day or every 20 samples, whichever is more frequent (typically laboratories using ten
samples compositing shall use the 0.01 μg ⁄mL standard to achieve a detection limit of 5 μg ⁄mL of Aroclor in any individual
sample). Sample results will be compared qualitatively with the daily IPS. (See the Calculation section 13).
11.1.2.1 Tabulate the sum of the areas or the data system calculated amount of the five major peaks for each of the Aroclors 1016
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and 1260 in the instrument performance standard. The response shall be within 50 % of the initial response. Initial response shall
be established by averaging the response of a minimum of five injections of the instrument performance standard (IPS). If the limit
is exceeded, new limits may need to be established.
11.1.2.2 Likewise, the expected response for the surrogate, if used, is established by averaging the areas of DCB in the five initial
IPS analyses.
11.1.2.3 The surrogate also may be used for retention time control. It is recommended that column flow be adjusted so DCB elutes
between 10.5 min to 11.5 min using the 12 min GC program. (This will typically require a column head pressure of 105 kPa to
112 kPa.) (Alternatively, the retention time should be 15 min to 16.5 min using the 17 min program.)
11.1.3 Tier 2–Quantitative Method—The GC data system must be calibrated for both Aroclors 1016 and 1260, using five peaks
for each Aroclor. [For example, when using an integrator, divide the standard amount by the number of peaks being used. Using
five peaks on a 0.5 μg ⁄mL standard would assign 0.1 μg ⁄mL to each peak. This will allow for a calibration table to be made,
yielding response factors for each peak at the five levels of calibration. Set up a calibration table in the method file of the integrator
or data system that is to be used. Calculate an average response factor for each of five peaks for both Aroclors. Calculate the
standard deviation of the average response factor for each peak of the Aroclor using the following calculation.
n
X 2 X
~ !
i
S 5Π(3)
(
n 2 1
i51
where:
S = standard deviation,
X = each observed value,
i
X = the arithmetic mean of observed values, and
n = total number of calibration points.
11.1.3.1 Calculate the percent relative standard deviations (% RSDs) for the response factors of the calibrated peaks for each
Aroclor from the formula below. The acceptance criteria for the % RSD for each Aroclor is ≤20 %. If the average % RSD is greater
than 20 % for either Aroclor, then linearity over the desired calibration range for that instrument has not been demonstrated.
NOTE 3—The % RSD is 100 % multiplied by the result of Eq 3 (s) divided by the
...