Document zQX68ZvaezGwNDJGedVjw1aqg

THE ANALYSIS OF POLYCHLORINATED BIPHENYLS IN TRANSFORMER FLUID AND WASTE OILS Scope 1.1 This Is a gas chromatography (GC) method applicable to the deter mination of commercial mixtures of polychlorinated biphenyls (PCBs) In transformer fluids and certain other hydrocarbon based waste oils. The method can be used to analyze waste oils for individual PC3 Isomers or complex mixtures of chlorinated biphenyls from aonochloroblphenyl through decachloroblphenyl only If they have bees previously Identified by other methods^ or by knowledge of^the. sample history. 1.2 The detection limits are dependent upon the complexity of the sample matrix and the ability of the analyst to properly maintain the analytical system. Using a carefully optimized instrument, this method has been shown to be useful for the determination of commercial PCS mixtures spiked Into transformer fluid over a range of 5.0 to 500 mg/Kg. Based upon a statistical calculation at 5 mg/Kg for a simple oil matrix, the method detection limit for Aroclors 1221, 1242, 1254, and 1260 Is 1 mg/Kg. The method U. 5. Environmental Protection Agency Office of Research and Development Environmental Monitoring and Support Laboratory Cincinnati, Ohio 45268 February 1981 HONS 003143 detection limit (MDl) Is defined as the minimum concentration of a . substance that can be measured and reported with 99X confidence that the value Is above zero. 1.3 This method Is restricted to use by or under the supervision of analysts experienced in the use of gas chromatography and In the Interpretation of gas chromatograms. Prior to sample analysis, each analyst must demonstrate the ability to generate acceptable results with this method by following the procedures described In Section 10.2. Summary , 2.1 The sample Is diluted on a weight/volume basis so that the concen trations of each PCB Isomer Is within capability of the gas chro matographic (SC) system (0.01 to 10 ng/uL). 2.2 The diluted sample Is then Injected Into a gas chromatograph for separation of the PCB Isomers. Measurement Is accomplished with a halogen specific detector which maximizes baseline stability and minimizes Interferences normally encountered with other detectors. The electron capture detector (ECO) can normally be substituted for the halogen specific detector, when samples contain dlchloro- through decachloroblphenyl Isomers (Aroclors 1232, 1242, 1016, 1246, 1254, 1260, 1262 and 1268) or when the sample matrix does not Interfere with the PC8s. Several cleanup techniques are provided for samples containing Interferences. A mass spectrometer oper ating In the selected Ion monitoring mode of data aqulsltlon may also be used as the SC detector, when PCB levels are sufficiently high and the PCB m/e ranges are free from Interference. Interfer- HONS 003144 I X V ences may occur In some waste oil samples even after exhaustive cleanup. 2.3 The concentrations of the PCBs are calculated on a mg/Kg basis, using conmerclal mixtures of PCBs as standards. The analysis time, not Including data reduction. Is approximately 35 mln/sample. 3. Interferences ' 3.1 Qualitative mlsldentlflcatlons are always a potential problem In SC. analysis. The use of a halogen specific detector and the analyst's skill In recognizing chromatographic patterns of comserclal PCS, . mixtures minimizes this possibility. 3.2 Whenever samples are analyzed that do not provide chromatographic patterns which are nearly Identical to the standards prepared from conmerclal PCBs, the analyst must confirm the presence of PCBs by analysis after column cleanup, analysis on dissimilar gas chromato graphic columns or by gas chromatography/mass spectrometry (GC/MS). 3.3 Ourlng the development and testing of this method, certain analyti cal parameters and equipment designs were found to affect the validity of the analytical results. Proper use of the method requires that such parameters or designs must be used as specified. These Items are Identified in the text by the word "must.* Anyone wishing to deviate from the method In areas so Identified, must demonstrate that the deviation does not affect the validity of the data. Alternative test procedure approval must be obtained through the EMSL-CI Equivalency Program^. An experienced analyst may make modifications to parameters or equipment Identified by the MGNS 003145 tins "recommended". Each time such modifications are made to the method, the analyst must repeat the procedure in Section 10.2. In this case, formal approval Is not required, but the documented data from 10.2 must be on file as part of the overall quality assurance program. 3.4 Samples diluted 100:1 analyzed by electron capture GC, consistently produce results that are 10 to 20X lower than the true value (Section 12). This Is due to quenching of the detector response by high boiling hydrocarbons coeluting with the PCBs. The degree Of error Is matrix dependent and Is not predictable for samples of. unknown origin. As the PCB .concentration approaches 20 percent of a control level, e.g., SO mg/kg, the analyst must routinely re analyze a duplicate spiked sample to determine the actual recovery. Spike the duplicate or diluted sample at 2 times the electron capture observed value and reanalyze according to Section 10.2. Correct the results accordingly. Apparatus 4.1 Gas Chromatograph - The gas chromatograph should be temperature programmable, equipped for on-column Injection, and capable of accepting 1/4 Inch 00 glass columns. 4.2 6as Chromatographic Detector 4.2.1 A halogen specific detector Is used to eliminate Interfer ences causing mlsldentlflcatlons or false-positive values due to non-organohalldes which comaonly coelute with the PBCs. a. Electrolytic conductivity detector the Hall Model 700-A HONS 003X46 ft. (HEO), available from Tracor, has been found to provide the sensitivity and stability needed for the current PC8 Regulations. b. Other halogen specific detectors, Including older model electrolytic conductivity detectors and mlcrocoulometrlc titration, may be used. However, the stability, sensi tivity, and response time of these detectors may raise the method detection limit and adversely affect peak resolution. Each system must be shown to be operating within requirements of the PCB regulations by collecting single laboratory accuracy and precision data and method detection limits on simple spiked samples as described In Section 10.2. '' 4.2.2 Semi-specif1c detectors such as ECD may be substituted when sample chromatographic patterns closely match those of the standards. Acid cleanup (Section 8.1) or Florlsll slurry cleanup (Section 8.7) should be Incorporated routinely when the ECO Is used. See Section 3.4 for additional quality control procedures for ECO. 4.2.3 Quantitative SC/MS techniques can be used and the recom mended approach Is selected Ion monitoring (SIN). The GC/MS data system must have a program that supports this method of data acquisition. The program must be capable of monitoring a minimum of eight Ions, and It Is desirable for the system to have the ability to change the Ions monitored as a function of time. For PCB measurements several sets of MONS 003147 r Ions may b used depending on the objectives of the study and the data system capabilities. The alternatives are as follows: Single Ions for high sensitivity Short mass ranges which may give enhanced sensi tivity depending on the data system capabilities Single Ions that give decreased sensitivity but are selective for levels of chlorination (1). 154, 188, 222, 256, 292, 326, 360, 394 154-156, 188-192, 222-226, 256-260, 290-295. 322-328, 356-364, 390-398 190, 224, 260, 294, 330, 362, 394 The data system must have the capability of Integrating the abundances of the selected Ions between specified. ' V.* limits, and relating Integrated abundances to concentra tions using the calibration procedures described In this method. 4.3 Sas Chromatographic Columns 4.3.1 The GC columns and conditions listed below are recoamended for the analysis of PCS mixtures In oil. If these columns and conditions are not adequate, the analyst may vary the coluan parameters to Improve separations. The columns and conditions selected must be capable of adequately resolving the PCBs In the various Aroclor mixtures so that each Aroclor Is Identifiable through Isomer pattern recognition. See Figures 1 through 6 to establish this. To properly use the calculation procedure described In Section 11.5, the analyst must use the methyl silicone column described In HONS 003148 4.3.2. Capillary columns and their associated specialized Injection techniques are acceptable alternatives to the recommended packed columns. Due to problems associated with the use of capillary columns the analyst must demonstrate that the entire system will produce acceptable results by performing the operations described in Section 10.2. 4.3.2 Recommended primary analytical column: Glass, 1/4 inch 0.0. (2 iwi I.D.) S ft (180 cm) long, packed with Gas-Chrom q (100/120 mesh) coated with 38 OV-1. Carrier gas: 40 to 60 ffll/mln (helium, nitrogen or 108 methane In argon). ' :; Temperature Program: 120C Isothermal for 2 minutes, 6/m1nute to 220C and hold until all compounds elute. Figure 6 shows a chromatogram of the PC8 locator mixture (see Section 5.8) analyzed under these conditions. Each PCB peak has been Identified by assigning the same relative retention times determined In the Isothermal runs Figures 1 through 6. Isothermal Operation: Aroclor 1221, 1232, or Cl^ through Cl^ Isomers 140 to 150C Aroclor 1016, 1242, 1254, 1260, 1262, 1268, or Clj through C11Q Isomers 170 to 200C 4.3.3 Recomnended confirmatory column: Glass tubing 1/4* 0.0., 2 mm 1.0. 6 ft (180 cm) long, packed with Gas-Chrom Q 100/120 mesh coated with 1.58 0V-17 + 1.958 OV-210. MOWS 003149 Carrier gas: 40 to 60 mL/mlnute (hellun, nitrogen or 10X methane In argon). Column temperatures: Aroclor 1221, 1232, or C1-, through Cl4 1somersil70 to 180C. Aroclor 1016, 1242, 1254, 1260. 1262, 1268, or Clj through C11Q 1somers-200C. 4.4 Volumetric flasks 10- 100- 200- and 250-mL 4.5 Pi pets - 0.10 ml, 1.0 mL, and 5.0 ml, Mohr delivery (for viscous oils cut off tip of plpet). 4.6 Micro syringes - 10.0 uL ^' 4.7 Sample containers - 20 mL or larger screw-cap bottles with ' faced cap liners. (Aluminum foil cap liners can be used for noses corrosive samples). 4.8 Chromatographic column - Chromaflex, 400 mm long x 19 did 10 (Kontes K-420540-9011 or equivalent). 4.9 Gel Permeation Chromatograph - GPC Autoprep 1002 or equivalent, available from Analytical Bio Chemistry Laboratories, Inc. 4.10 Balance Analytical, capable of accurately weighing 99 t .0001 grams. 4.11 Kuderna-Oanlsh (K-0) Apparatus 4.10.1 Concentrator tube-10 mL, graduated (Kontes K-570050-1025 or equivalent). Calibration must be checked. Ground glass stopper (size 19/22 Joint) Is used to prevent evaporation of solvent. 4.11.2 Evaporative flask - 500 mL (Kontes K-57001-0500 or HONS 003150 s equivalent). Attach to concentrator tube with springs (Kontes K-662750-0012). 4.11.3 Snyder column - Three-ball macro (Kontes K503000-0121 or ' equivalent). - 5. Reagents and Materials 5.1 Reagent safety precautions 5.1.1 The toxicity or carcinogenicity of each reagent used In this method has not been precisely defined; however, each chemi cal compound should be treated as a potential health haalrd. From this viewpoint, exposure to these chemicals must; be.' reduced to the lowest possible level by whatever means available. The laboratory Is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemical sspeclfled In this method. A reference file of material data handling sheets should also be made available to all personnel Involved In the chemical analysis. 5.1.2 Polychlorinated biphenyls have been tentatively classified as known or suspected, hunan or manualIan carcinogens. Primary standards of these toxic compounds should be pre pared In a hood. 5.1.3 Diethyl ether should be monitored regularly to determine the peroxide content. Under no circumstances should diethyl ether be used with a peroxide content In excess of 50 ppm as an explosion could result. Peroxide test strips manufac tured by EM Laboratories (available from Scientific Products MOWS 003151 Co. Cat. No. PIT26-8 and other suppliers) are recommended for this test. Procedures for removal of peroxides from diethyl ether are Included in the Instructions supplied with the peroxide test kit. ' 5.2 Hexane (mixed hexanes). Isooctane, acetonitrile, methylene chloride, cyclohexane, and diethyl ether - Pesticide grade. 5.3 Column packings (recommended) 5.3.1 Gas Chrom Q (100/120 mesh) coated with 3X OV-1. 5.3.2 Gas Chrom q (100/120 mesh) coated with 1.5X 0V-17 1.95* ov-210. 5.4 Standards . 5.4.1 Aroclors 1221, 1232, 1242, 1016, 1254, 1260, 1262, 1W, ; Primary dilutions of various Aroclors In Isooctane will M available from U.S. EPA, EMSL-Clnelnnatl Quality Assurance Branch, 26 M. St. Clair Street, Cincinnati, Ohio 45263. 5.4.2 2-Chloroblphenyl, 3-chloroblphenyl, and decachloroblphenyl 5.4.3 Pure Individual PCBs as Identified In the sample by mess spectrometry or Indicated by retention data. 5.4.4 Alumina (Fisher A540 or equivalent). 5.4.5 Silica gel (Davison Grade 950 or equivalent). 5.4.6 Florlsll (PR grade or equivalent). 5.4.7 Sulfuric acid A.C.S. 5.4.8 Quality Control Check Sample, Certified Sample of PCBs In oil available from U.S. EPA, EMSL-Clnelnnatl Quality Assurance Branch, 26 W. St. Clair Street, Cincinnati, Ohio 45268. MOMS 003152 5.5 Standard Stock Solutions - Prepare primary dilutions of each of the' Aroclors or Individual PCBs by weighing approximately 0.01 g of material within t 0.0001 g. Olssolve and dilute to 10.0 ml with Isooctane or hexane. Calculate the concentration In ug/ul. Store . the primary dilutions at 4C In 10 to 15 ml narrow-mouth, screw- cap bottles with Teflon cap liners. Primary dilutions are stable Indefinitely If the seals are maintained. The validity of primary and secondary dilutions must be monitored on a quarterly basis by analyzing EMSL-CI Quality Control Check Samples. 5.5 Working Standards - Prepare working standards similar In PC8 cflp - position and concentration to the samples by mixing and diluting the Individual standard stock solutions. Dilute the m1xturartw> volume with pesticide quality hexane. Calculate the concentration In ng/uL as the Individual Aroclors or as the Individual PCBs. Store dilutions at 4C In 10- to 15-ml narrow-mouth, screw-cap " bottles with Teflon cap liners. These secondary dilutions can be stored Indefinitely If the seals are maintained. 5.7 laboratory control standard (LCS) - Prepare a ICS by spiking a PCB-free oil, typical of the matrix normally analyzed, at 50.0 mg/Kg (l.e. transformer oil) with a PC8 mixture typical of those normally found In the samples (l.e. Aroclor 1260 at 50.0 mg/Kg). 5.8 PCS Locator Mixture - Prepare a PCB locator mixture containing 0.1 ng/ul of 2-chloroblphenyl, 0.1 ng/ul 3-chloroblphenyl, 0.5 ng/uL Aroclor 1242, 0.5 ng/uL Aroclor 1260, and 0.2 ng/ul Aroclor 1268 In hexane (0.1 ng/ul of decachloroblphenyl can be substituted for Aroclor 1268). Use the chromatogram generated by the PCB locator HONS 003153 mixture to help Identify the retention times of the various PCS Isomers commonly found In commercial PCB mixtures. Sample Collection and Handling 6.1 Sample containers should have a volume of 20 mL or more and have Teflon lined screw caps. 6.2 Sample Bottle Preparation 6.2.1 Wash all sample bottles and seals In detergent solution. Rinse with tap water and then distilled water. Allow the bottles and seals to drain dry In a contaminant free area. Then rinse seals with pesticide grade hexane and allow to air dry. 6.2.2 Heat sample bottles to 400C for 15 to 20 min or rinse with pesticide grade acetone or hexane and allow to air dry. 6.2.3 Store the clean bottles Inverted or sealed until use. 6.2.4 Prior to reuse, rinse the bottles and seals 3 times with hexane, air dry, and then proceed to 6.2.1. 6.3 Sample Preservation - The samples should be stored in a cool, dry, dark area until analysis. Storage times In excess of 4 weeks are not recommended for unknown or undefined sample matrices. 6.4 Sample Collection 6.4.1 Fill a large container (1.e. 500-mL beaker) from a represen tative area of the sample source (If practical, mix the sample source prior to sampling). 6.4.2 Collect a minimum of two 20-mt. samples (Field Sample 1 (FS1) and Field Sample 2 (FS2)) approximately BOX full from the sampling container. HONS 003164 T 6.4.3 Repeat 6.4.1 and 6.4.2 if there is a need to monitor sampling precision as described in Section 10.6. 7.011utlon and Analysis 7.1 The approximate PC8 concentration of the sample may be determined by X-ray fluorescence, microcoulomatry, density measurements, or by analyzing a very dilute mixture of the sample (10,000:1) according to 7.1. 7.2 for samples in the 0 to 100 mg/Kg range, dilute 100:1 in hexane. 7.2.1 Pipet 1.0 mL of sample into a 100 mt volumetric flask using a 1.0-mL Mohr pipet (for viscous samples, cut the capillary tip off the pipet). Dilute to volume with hexane. Stopper and mix. 7.2.2 Using the same pipet as in 7.2.1, deliver 1.0-mi of sample into a tared 10-mi beaker weighed to t .001 g. Reweigh the beaker to * .001 g to determine the weight of sample used in 7.2.1. 7.2.3 As an alternative to 7.2.1 and 7,2.2, weigh approximately 1 gram to +.001 g of sample in a volumetric flask and dilute to 100-mi In hexane. 7.2.4 Analyze the diluted sample according to 7.4 or store the diluted sample in a narrow-mouth bottle with a Teflon lined screw-cap. 7.3 For samples above 100 mg/Kg in concentration, dilute 1000:1 in hexane. 7.3.1 Pipet 0.10 ml of sample into a 100-mt volumetric flask using a 0.10 ml Mohr pipet. Dilute to volume with hexane, stopper and mix. MONS 003155 7.3.2 Using the same pi pet as in 7.3.1, deliver 0.10 ml of sample into a tared 10 ml beaker to .0001 g. Reweigh the beaker to determine the weight of sample used in 7.3.1. 7.3.3 As an alternative to 7.3.1 and 7.3.2, weigh approximately 0.1 gram to .0001 g of sample and In a 100 ml volumetric flask dilute to volume with hexane. 7.3.A Analyte the diluted sample according to 7.4 or store the diluted sample In a narrow-mouth bottle with a Teflon-lined screw-cap. 7.3.5 If the concentration of PCSs is still too high for the chromatographic system, prepare secondary dilutions from 7.3.1 or 7.3.3 until acceptable levels are obtained. 7.4 Analyze the sample by injecting the hexane mixture into the gas chromatograph using auto Injectors or the solvent flush tech nique^. Note: When semi-specific detectors are used, cleanup techniques (See Section 4.2.2) should be routinely Incorporated into the analysis scheme prior to Injection. 7.4.1 Recommended injection volumes: Halogen specific detector - 4 to 5 ul, electron capture detector-2 to 3 ul. Smaller volumes may be Injected when auto Injectors are used If the resulting method detection limits are acceptable. 7.5 If the resulting chromatogram shows evidence of column flooding or nonlinear responses due to excess sample, further dilute the sample ' according to 7.3.5. 7.6 Determine whether or not PCBs are present In the sample by HONS 003156 comparing the sample chromatogram to that of the PCS locator mixture Section 5.8. 7.6.1 If a series of peaks In the sample match some of the reten tion times of PC8s In the PC8 locater mixture, attempt to Identify the source by comparing chromatograms of each standard prepared from commercial mixtures of PC8s (See Section 5.6). Proceed to Section 11.4 If the source of PC8s Is Identified. 7.6.2 If the sample contains a complex mixture of PC8s, proceed to Section 11.5. 7.6.3 If a 1000:1 or higher dilution ratio sample was analyzed and no measurable PC8 peaks were detected, analyze an aliquot Of sample diluted to 100:1. 7.6.4 If several PC8 Interference problems are encountered or If PC8 ratios do not match standards, proceed to Section 8, use alternate columns, or use GC/MS to verify whether or not the nonrepresentative patterns are due to PCSs. Cleanup - Several tested cleanup techniques are described. Depending upon the complexity of the sample, one or all of the techniques may be required to resolve the PCBs from Interferences. 8.1 Acid Cleanup 8.1.1 Place 5.0 ml of concentrated sulfuric acid Into a 40-mL narrow-mouth screw-cap bottle. Add 10.0 ml of the diluted sample. Seal the bottle with a Teflon-lined screw-cap and shake for 1 minute. 8.1.2 Allow the phases to separate, transfer the sample (upper HONS 003157 phase) to a clean narrow-mouth screw-cap bottle. Seal with a Teflon-lined cap. 8.1.3 Analyze according to Section 7.4. 3.1.4 If the sample Is highly contaminated, a second or third acid cleanup may be employed. NOTE: This cleanup technique was tested over a period of about 6 months using both electron capture and electrolytic conductivity detectors. Care was taken to exclude any samples that formed an emulsion with the acid. The sample was withdrawn well above the sample-acid Interface. Under these conditions no adverse effects associated with column performance and detector sensitivity to PC8s were noted. This cleanup technique could adversely affect the chromato graphic column performance for future acid degradable samples. 8.2 FT or 1s11 Column Cleanup 8.2.1 Variances between batches of florlsll may affect the elution volume of the various PCBs. For this reason, the volume of solvent required to completely elute all of the PC8s must be verified by the analyst. The weight of Florlsll can then be adjusted accordingly. 8.2.2 Place a 20.0 g charge of Florlsll, activated at 130C, Into a Chromaflex column. Settle the Florlsll by tapping the column. Add about 1 cm of anhydrous sodium sulfate to the top of the Florlsll. Pre-elute the column with 70 to 80 ml of hexane. Just before the exposure of the sodium MONS 0031.58 sulfate layer to air, stop the flow. Oiscard the eluate. 8.2.3 Add 2.0 mL of the undiluted sample to the column with a 2- mL Mohr pipet. (For viscous samples, cut the capillary tip off the pipet.) Add 225 mL of hexane to the column. Carefully wash down the inner wall of the column with a small amount of the hexane prior to adding the total volume. Collect and discard the first 25.0 ml. 8.2.4 Collect exactly 200 mL of hexane eluate in a 200-mL volu metric flask. All of the PC3s must be in this fraction. 8.2.5 Using the same pipet as in 8.2.2, deliver 2.0 mL of sample into a tared 10 mL beaker weighed to t 0.001 g. Reweigh the beaker to determine the wfeignt of the sample diluted to 200 mL. 8.2.6 Analyze the sample according to Section 7.4. 8.3 Alumina Column Cleanup 8.3.1 Adjust the activity of the alumina by heating to 200C for 2 to 4 hours. When cool, add 3% water (wt:wt) and mix until uniform. Store In a tightly sealed bottle. Allow the deactivated alumina to equilibrate at least 1/2 hr before use. Reactivate weekly. 8.3.2 Variances between batches of alumina may affect the elution volume of the various PC8s. For this reason, the volume of solvent required to completely elute all of the PC8s must be verified by the analyst. The weight of Alumina can then be adjusted accordingly. 3.3.3 Place a 50.0 g charge of alumina into a Chromaflex column. HONS 003159 Settle the alumina by tapping. Add about 1 cm of anhydrous sodium sulfate. Pre-elute the column with 70 to 80 ml of hexane. Just before exposure of the sodium sulfate layer to air, stop the flow. Discard the eluate. . 8.3.4 Add 2.5 ml of the undiluted sample to the column with a 5-mL Mohr plpet. (For viscous samples, cut the capillary end off the pipet.) Add 300 mu of hexane to the column. Carefully wash down the Inner walls of the column with a small volume of hexane prior to adding the total volume. Collect and discard the 0 to 50 mL fraction. 8.3.5 Collect exactly 250 mL of the hexane In a 250-mL volumetric flask. All of the PCBs must be In this fraction. 8.3.6 Using the same plpet as In 8.3.4, deliver 2.5 mL of sample Into a tared 10-mL beaker * 0.001 g. Reweigh the beaker to determine weight of sample diluted to 250 mL. 8.3.6 Analyte the sample according to Section 7.4. 8.4 Silica Sel Column Cleanup. 8.4.1 Activate silica gel at 135C overnight. 8.4.2 Variances between batches of silica gel may affect the elution volume of the various PCBS. For this reason, the volume of solvent required to completely elute all of the PCBs must be verified by the analyst. The weight of silica gel can then be adjusted accordingly. 8.4.3 Place a 25 g charge of activated silica gel into a Chroma- flex column. Settle the silica gel by tapping the column. Add about 1 cm of anhydrous sodium sulfate to the top of the silica gel. MOMS 003160 t 8.4.4 Preelute the column with about 70 to 80 ml of hexane. Discard the eluate. Just before the exposure of the sodium sulfate layer to air, stop the flow. 8.4.5 Add 2.0 mL of the undiluted sample to the column with'a 2-mL Mohr plpet. (For viscous samples, cut the capillary tip off the plpet.) 3.4.6 Wash down the Inner wall of the column with 5 ml of hexane. 3.4.6 Elute the PCBs with 195 ml of 10% dlethylether In hexane V:V. 9.4.3 Collect exactly 200 si of the eluate In a 200-mL volumetric flask. All of the PC3s must be In this fraction. 8.4.9 Using the same plpet as in 8.4.5, deliver 2.0 mb of sample Into a tared 10-mL beaker (t 0.001 g). Reweigh to determine the weight of sample diluted to 200 mL. 8.4.10 Analyze the sample according to Section 7.4. 8.5 Sel Permeation Cleanup 8.5.1 Set up and calibrate the gel permeation chromatograph with an SX-3 column according to the Instruction manual. Use 15X methylene chloride In cyclohexane (V:V) as the mobll phase. 8.5.2 Place 1.0 mL of sample Into a 100-mL volumetric flask, using a 1-mL Mohr plpet. (For viscous samples, cut the capillary tip off the plpet.) 8.5.3 Dilute the sample to volume, using 15% methylene chloride In cyclohexane (V:V)8.5.4 Using the same plpet as In 8.5.2 deliver 1.0 mL of sample Into a tared 10-mL beaker t 0.001 g. Reweigh the beaker i 0.001 g to determine the weight of sample used In 8.5.2. HONS 003161 T 8.5.5 As an alternative to 8.5.2 and 8.5.3 weigh approximately 1 ' gram 0.001 g of sample and dilute to 100.0 mL in 15% methylene chloride in cyclohexane (V:V). 8.5.6 Inject 5.0 mL of the diluted sample Into the Instrument. Collect the fraction containing the Cl, through Cl,g PCBs (see operator's manual) in a K-0 flask equipped with a 10-mL ampul. 8.5.7 Concentrate the 8.5.4 fraction down to less than 5 mL. Using K-0 evaporative concentration techniques. 3.5.8 Dilute to 5.0 mL with hexane, then analyze according to Section 7.4. Be sure to use 100 mL as the dilution volume for the final calculation. 8.6 Acetonitrile Partition 8.6.1 Place 10.0 mL of the previously diluted sample Into a 125-mL separatory funnel with enough hexane to bring the final volume to 15 mL. Extract the sample four times by shaking vigorously for one minute with 30-mL portions of hexanesaturated acetonitrile. 8.6.2 Combine and transfer the acetonitrile phases to a one-liter separatory funnel and add 650 mL of distilled water and 40 mL of saturated sodium chloride solution. Mix thoroughly for 30 to 35 seconds. Extract with two 100 mL portions of hexane by vigorously shaking about 15 seconds. 8.6.3 Combine the hexane extracts in a one-lfter separatory funnel and wash with two 100-mL portions of distilled water. Discard the water layer and pour the hexane layer through a HON* 3 to 4 Inch anhydrous sodium sulfate column into a 500-ml K-D flask equipped with a 10 ml ampul. Rinse the separa tory funnel and column with three 10 ml portions of hexane. 8.6.4 Concentrate the extracts to 6 to 10 ml In the K-D evaporator in a hot water bath, then adjust the volume to 10.0 ml. Be sure to use the correct dilution volume (8.5.1) for the final calculation. 8.6.5 Analyte according to Section 7.4. 3.7 Morisil Slurry Cleanup 8.7.1 Place 10 ml of the diluted sample Into a 20-ml narrow-mouth screw cap container. Add 0.25 g of Florlsll.. Seal with a Teflon lined screw cap and shake for 1 minute. 8.7.? Allow the Florlsll to settle then decant the treated solu tion Into a second container. Analyte according to Section 7.4. Calibration 9.1 Single Point Calibrations - Prepare calibration standards from standard stock solutions In hexane that are close to the unknown In composition and in concentration. When using an electrolytic con ductivity detector, if the sample response is In the low level nonlinear detection area, then the calibration point must be within 20* of the sample. The ECO must be operated only within Its linear response range. 9.2 As an alternative to 9.1, prepare a calibration curve for each Aroelor or PCB detected In the sample. The standard curve must HONS 003163 T contain at least 3 points, two of which inust bracket the sample concentration. When using an electrolytic conductivity detector. If the sample response Is In a low level nonlinear area of the calibration curve, two of the calibration points must be within 20* of the unknown. The calibration curve must be checked dally, using the Quality Check Sample Section 5.7. If the calibration curve Is not within 15 percent of the Quality Check Sample, recalibrate the Instrument. It will be necessary to correct electron capture data for recovery (See Section 3.4). Use the recovery value determined the same day the calibration curve was generated. The corrected value must be within 15* of the spike value, otherwise the Instru ment must be recalibrated. 10. Quality Control 10.1 Each laboratory that uses this method Is required to operate a formal quality control program. The minimum requirements of this program consists of an Initial demonstration of laboratory capa bility and the analysis of spiked samples as a continuing check on performance. The laboratory Is required to maintain performance records to define the quality of data that is generated. After January 1, 1982. ongoing performance checks must be compared with established performance criteria to determine If the results of analyses are within accuracy and precision limits expected of the method. 10.1.1 Before performing any analyses, the analyst must demonstrate the ability to generate acceptable accuracy and precision with this method. This ability Is established as described in Section 10.2. moms 0O314>'* 10.1.2 In recognition of the rapid advances that are occurring In chromatography, the analyst is permitted certain options to Improve the separations or lower the cost of measurements. Each time such modifications are made to the method, the analyst is required to repeat the procedure In Section 10.2. 10.1.3 The laboratory must spike and analyze a minimum of 10 percent of all samples to monitor continuing laboratory performance. This procedure is described In Section 10.4. 10.2 To establish the ability to generate acceptable accuracy and precision In the use of this method, the analyst must perform the following operations. 10.2.1 For each commercial PCS mixture or Individual PCS normally measured, select a spike concentration representative of high Interest levels In the samples (25 to 75 mg/kg). Using stock standards, prepare a quality control cheek sample concentrate In Issoctane 1000 times more concentrated than the selected concentrations. 10.2.2 Using a microsyringe, add ICO uL of the check sample concen trate to each of a minimum of four 100-ml aliquots of PC3-free oil. A representative waste oil may be used In place of the clean oil, but one or more additional aliquots must be analyzed to determine background levels, and the spike level must exceed twice the background level for the test to be valid. Analyze the aliquots according to the method beginning In Section 7. 10.2.3 Calculate the average percent recovery, (R), and the HONS 003165 relative standard deviation of the concentration found. Waste oil background corrections must be made before R calculations are performed. 10.2.4 Using the appropriate data from Tables 7, S, and 9, deter mine the recovery and single operator precision expected for the method and compare these results to the values calcu lated In Section 10.2.3. If the data are not comparable, the analyst must review potential problem areas and repeat the test. 10.2.5 After January 1, 1982, the values for R and s must meet method performance criteria provided by the U.S. EPA, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, before any samples may be analyzed. 10.3 The analyst must calculate method performance criteria and define the performance of the laboratory for each spike concentration and parameter being measured. 10.3.1 Calculate upper and lower control limits for method perform ance: Upper Control Limit (UCL) * R + 3 s Lower Control Limit (LCL) * R - 3 s where R and s are calculated as In Section 10.2.3. The UCL and LCL can be used to construct control charts^ that are useful In observing trends In performance. After January 1, 1982, the control limits above must be replaced by method performance criteria provided by the U.S. Environmental Protection Agency. HONS 003166 T 10.3.2 The laboratory must develop and maintain separate accuracy statements of laboratory performance for waste oil samples. An accuracy statement for the method Is defined as A i s. The accuracy statement should be developed by the analysis of four aliquots of waste oil as described in Section 10.2.2, followed by the calculation of R and s. Alter nately, the analyst may use four waste oil data points gathered through the requirement for continuing quality control In Section 10.4. The accuracy statements should be updated regularly. 10.4 The laboratory Is required to collect a portion of their samples In duplicate to monitor spike recoveries. The frequency of spiked sample analysis must be at least 10X of all samples or one sample per month, whichever Is greater. One aliquot of the sample must be spiked and analyzed as described in Section 10.2. If the recovery for a particular parameter does not fall within the control limits for method performance, the results reported for the parameter in all samples processed as part of the same set must be qualified as described In Section 11.9. The laboratory should monitoring the frequency of data so qualified to ensure that It remains at or below 5X. 10.5 Before processing any samples, the analyst should demonstrate through the analysis of a PCB-free oil sample, that all glassware and reagent Interferences are under control. Each time a set of samples Is analyzed or there is a change in reagents, a laboratory reagent blank should be processed as a safeguard against contamin ation. HONS 003169 10.6 It Is recomnended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to monitor the precision of the sampling technique. When doubt exists over the Identification of a peak on the chromatogarm, confirmatory techniques such as gas chromatography with a dis similar column, specific element detector, or mass spectrometer must be used. Whenever possible, the laboratory should perform analysis of standard reference materials and participate In relevant performance evaluation studies. 10.7 Analyze the quality control check sample Section 5.7 dally before any samples are analyzed. Instrument status checks, calibration curve validation and long term precision are obtained from these data. In addition, response data obtained from the quality control check standard can be used to estimate the concentration of the unknowns. From this Information, the appropriate standard dilu tions can be determined for single point calibrations. 10.8 Quarterly, analyze an EMSL-Clnclnnatl Quality Control Sample (Section 5.4.8) of PCBs In oil or whenever new standard dilutions are prepared. 10.8.1 The results of the EMSl Quality Control Sample should agree within 20X of the true value. If they do not, the analyst must check each step In the standard preparation procedure to solve the problem. 11. Calculations HONS 003168 11.1 Locate each PCS In the sample chromatogram by comparing the reten tion time of the suspect peak to the retention data gathered from analyzing standards and Interference free Quality Control Samples. The width of the retention time window used to make Identifications should be based upon measurements of actual retention time vari ations of standards over the course of a day. Three times the standard deviation of a retention time for each PC8 can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily In the Interpretation of chromatograms. 11.2 If the response for the peak exceeds the working range of the system, dilute according to Section 7.3.5. 11.3 If the measurment of the peak response is prevented by the presence of Interferences, further cleanup Is required. 11.4 If the parent Aroclor(s) or. PC3(s) are identified In the sample, calibrate according to Section 9. The concentration of the PC3s In the sample are calculated by comparing the sum of the responses for each PC8 In the standard to the sum of all of the PC8s In the sample. This Is particularly Important as sample concentrations approach within 20 percent of 50 mg/kg or any other EPA regulated concentration. If calculations are based upon a single PC8 peak or upon a small percentage of the total PC8 peaks, serious errors may result. Peaks comprising less than SOX of the total can be dis regarded only If 1) Interference problems persist after cleanup, 2) when the source of PC8s is obvious 3) when the concentration of PCBs are not within 20X of an EPA controlled value l.e., 50 mg/kg. MQNS 003169 11.4.1 Measure the peak height or peak area of each peak identified as a PC8 in 11.1 in both the sample and the standard. 11.4.2 Use the following formula to calculate the concentration of PCBs in the sample: Concentration mg/Kg 9 * vt A x W" A Sum of standard Peak Heights (areas) _ __ ----------- ng of"standard injected---------- 'm/n<} R m Sum of sample Peak Heights (areas) B* ul Injected mm/uL Vt> dilution volume of sample in ml W weight of the sample in grams 11.5 If the parent Aroclor(s) or source of PCSs is not apparent, calcu late the concentration according to the procedure of Webb and McCall (5). The concentration of each PCS is determined individu ally then added together to determine the total PC8 content of the sample. Each PCS Identified In the sample must be Included in these calculations. 11.5.1 Small variations between Aroclor batches make it necessary to obtain standards prepared from a specific source of Aroclors. Primary dilutions of these reference Aroclors will be available In 1981 from the Environmental Monitoring and Support Laboratory, Quality Assurance Branch, Cincinnati, Ohio 45268. 11.5.2 Analyze a standard mixture of Aroclors 1242, 1254 and 1260 under the conditions shown In Figures 3, 5, and 6. Analyze the sample under the same conditions. Compare the resulting MONS 003170 standard chromatograms to those shown In Figures 3, 5, and 6. Each PCa peak must be resolved as well or better than those shown fn the figures. Oetermine the relative reten tion time (RRT) of each peak In the standards with respect to p,p`-D0E or assign the RRT shown in the figures to the corresponding peak In the standard. Identify the RRT of each PCS In the sample by comparing the sample chromatogram to the standard chromatograms. 11.5.3 Identify the most likely Aroclor(s) present In the sample, using the Identification Flow Chart Figure 7. 11.5.4 Analyze standards according to Section 9, using the appro priate Aroclors. 11.5.5 Determine the Instrument response factor (A) for each Individual PC8, using the following formula: .m * Peak Height (area) No, x mean weight X 1 --fat) -- Ngi Ng of Aroclor standard injected Obtain mean weight percent from Tables 1 through 6. 11.5.5 Calculate the concentration of each PC8 In the sample using the following formula: Concentration mg/Kg ** x Vt Ax W A Response factor from 11.4.5 B Peak Height (areas) of sample mm/ul lit. Injected V[* dilution volume of sample In mL W weight of sample In grams HONS 003171 The concentration of each PCS must be calculated and added together to obtain the total amount of PC3s present. 11.6 Report all data In mg/Kg. 11.7 Round off all data to 2 significant figures. ' 11.8 Sun all Aroclors and report what was used as the standard. For example, 57 mg/Kg measured as Aroclor 1260 or 57 mg/Kg measured as Aroclors 1242 and 1260. 11.9 For samples processed as part of a set where the laboratory spiked sample recovery falls outside of the control limits In Section 10.4, data for the affected parameters must be labeled as suspect. 11.10 For electron capture analyses determine the actual recovery for each sample In the uncorrected 40 to 50 mg/kg concentration range (see Section 3.4). Report the corrected value and the recovery. 12. Single Laboratory Accuracy and Precision 12.1 The single laboratory data shown In Tables 7 through 9 were generated using the recommended procedures described In this method to analyze both spiked and nonsplked oil samples of varying degrees of complexity using a halogen specific detector and an electron capture detector. These data were generated by the Physical and Chemical Methods Branch, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, 45268. References 1. Elehelberger, J. W., L.E. Harris, and W. L. Budde, Anal. Chem., 46, 227 (1974). -- 2. Federal Register, Vol. 41, No. 232, Wednesday, Oecember 1, 1976. 3. White, L. 0., et al., AIHA Journal. 31, 22S, (1970). 4. "Handbook of Analytical Quality Control In Water and Wastewater Laboratories," EPA-600/4-79-019, U.S. Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, March 1979. 5. Webb, R.G., and A.C. McCall, 0. Chrom. Scl.. 11, 366 (1973). HONS 003172 T RRT& TA8LE 1 Composition of Aroclor 1221 Mean Weight Percent Relative Std. Dev. Number of Chlorines d - 11 14 16 19 21 28 32 37 40 Total 31.8 19.3 10.1 2.8 20.8 5.4 1.4 1.7 93.3 15.8 9.1 9.7 9.7 9.3 13.9 30.1 48.8 . i i 2 2 2 2 85% 3 15X 2 10X 3 90X 3 3 * data obtained from (5). b Retention time relative to p,p'-D0*100. Measured from first appearance of solvent. Overlapping peaks that are quantitated as one peak are bracketed. c Standard deviation of seventeen results as a percentage of the mean of the results d From GC-MS data. Peaks containing mixtures of Isomers of different chlorine numbers are bracketed. MOMS 003173 . RRT6 TABU 2 Composition of Aroclor 1232* Mean Weight Percent Relative Std. Oev. c Number of Chlorines d 11 14 16 20 21 28 32 37 40 47 54 58 70 78 Total 16.2 9.9 17.8 17.8 9.6 3.9 6.8 6.4 4.2 3.4 2.6 4.6 1.7 94.2 3.4 2.5 2.4 2.4 3.4 4.7 2.5 2.7 4.1 3.4 3.7 3.1 . 7.5 1 1 2 2 2 2 40% 3 60% 3 3 3 4 3 33% 5 67% 4 4 90% 5 10% 4 * Data obtained from (5). b Retention time relative to p,p'-0DE*100. Measured from first appearance of solvent. Overlapping peaks that are quantitated as one peak are bracketed. c Standard deviation of four results as a mean of the results. d From SC-MS data. Peaks containing mixtures of Isomers of different chlorine numbers are bracketed. HONS 003174 I RRT6 11 16 21 28 32 37 10 47 54 58 70 78 84 98 104 146 Total TABLE 3 Composition of Aroelor 1242* Mean Weight Percent Relative Std. Dev. c Number of ' Chlorines d 1.1 2.9 11.3 11.0 6.1 11.5 n.i 8.8 6.8 5.6 10.3 3.6 2.7 1.5 1.6 1.0 98.5 35.7 4.2 3.0 5.0 4.7 5.7 6.2 4.3 2.9 3.3 2.8 4.2 9.7 9.4 20.4 19.9 1 2 2 2 25X 3 75X 3 3 3 4 3 33X 4 67X 4 4 90X 5 10X 4 5 5 5 85X 6 15X 5 75X 6 25X * Dt* obtained from (). b Retention time relative to p,p'-OOE*100. Measured from first appearance of solvent. c Standard deviation of six results as a percentage of the man of the results. 4 From GC-MS data. Peaks containing mixtures of Isomers of different chlorine numbers are bracketed. HONS 003173 RRT6 21 28 32 47 40 47 54 53 70 78 84 98 104 112 125 148 Total TA8LE 4 Composition of Aroclor 12484 Mean Height Percent Relative Std. Dev. c Number of Chlorines d* 1.2 5.2 3.2 8.3 8.3 15.6 9.7 9.3 19.0 6.6 4.9 3.2 3.3 1.2 2.6 1.5 103.1 23.9 3.3 3.8 3.6 3.9 1.1 6.0 5.8 1.4 2.7 2.6 3.2 3.6 6.6 5.9 10.0 2 3 3 3 3 85X 4 15X 4 3 10X 4 90X 4 4 80X 5 20X 4 5 5 4 10X 5 90X 5 5 90X 6 10X 5 85X 6 15X * Data obtained from (5). b Retention time relative to p,p'-00E"100. Measured from first appearance of solvent. ' e Standard deviation of six results as a percentage of the mean of the results. d From GC-MS data. Peaks containing mixtures of isomers of different chlorine numbers are bracketed. HONS 003i7b RRT6 TABU 5 Composition of Aroclor 1254* Mean Weight Percent Relative Std. Oev. e Number of Chlorines 1 47 54 58 70 84 98 104 125 146 160 174 203 232 Total 6.2 2.9 1.4 13.2 17.3 7.5 13.6 15.0 10.4 1.3 8.4 1.8 1.0 100.0 3.7 2.6 2.8 2.7 1.9 5.3 3.8 2.4 2.7 8.4 5.5 18.6 26.1 4 4 4 4 25X 5 75X 5 .5 5 5 70X 5 30X 5 30X 6 70X 6 6 6 7 * Data obtained from (5). 11 Attention time relative to p,p'-DDE*100. Measured from first appearance of solvent. c Standard deviation of six results as a percentage of the mean of the results. d From SC-MS data. Peaks containing mixtures of Isomers of different chlorine numbers are bracketed. HONS 003177 T ART6 70 84 96 104 117 12S 146 160 174 203 232 244 280 332 372 448 528 Total ' TABLE 6 . Composition of Aroclor 1260* Mean Weight Percent 2.7 4.7 3.3 3.3 12.3 14.1 4.9 12.4 9.3 9.8 11.0 4.2 4.0 .6 1.5 98.6 Relative Std. Oev. 6 6.3 1.6 3.5 5.7 3.3 3.6 2.2 2.7 4.0 3.4 2.4 5.0 3.6 25.3 10.2 Number- of Chlorines 6 5 5 e 5 60S 6 40% 6 5 15* 6 35% 6 6 50% 7 50% 6 6 10% 7 90% f 6 10% 7 90% 7 7 8 8 8 . * Oata obtained from (5). 6 Retention time relative to p,p'-ODE100. Measured from first appearance of solvent. Overlapping peeks that are quantitated as one peak are bracketed. e Standard deviation of six results as a mean of the results. d Frost GC-MS data. Peaks containing mixtures of Isomers of different chlorine numbers are bracketed. * Composition determined at the center of peak 104. f Composition determined at the center of peak 232. HONS 003178 T TABLE 7 ACCURACY AND PRECISION USING SPIKED MOTOR OIL i Hutton Method Ratio Detector Clean-i Spike mg/Kg Aroclor Spike Ave. Cone. Found mg/Kg [Precision) Rel. Std. Deviation t (Accuracy) Percent Recovered Humber of Dilution 00:1 'JO: 1 00:1 00:1 CO: 1 00:1 00:1 00:1 L"J: 1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 00:1 30:1 00:1 00:1 00:1 30:1 00:1 30:1 HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HED ECO HEO ECO None None None None 8.1 8.1 8.1 8.1 8.2 8.2 8.2 8.2 8.3 8.3 8.3 8.3 8.4 8.4 8.4 8.4 8.5 8.5 8.5 8.5 8.6 8.6 8.6 8.6 30.3 30.3 31.1 31.1 30.3 30.3 31.1 31.1 30.3 30.3 31.1 31.1 30.3 30.3 31.1 31.1 30.3 30.3 31.1. 31.1 30.3 30.3 31.1 31.1 30.3 31.1 30.3 31.1 1242 1242 1260 1260 1242 1242 1260 1260 1242 1242 1260 1260 1242 1242 1260 1260 1242 1242 1260 1260 1242 1242 1260 1260 1242 1242 1260 1260 28.2 26.7* 27.2 23.9 28.4 25.4* 28.1 24.3 30.7 27.3* 30.9 31.0 30.3 28.9* 29.8 30.8 29.4 26.4* 29.4 23.6 31.9 23.4* 33.6 30.9 34.4 23.4* 29.1 27.0 4.2 5.7 2.0 2.2 11.5 6.1 8.0 7.8 2.4 10.2 3.6 8.6 8.6 5.0 4.7 6.5 5.8 5.3 5.2 4.5 8.5 3.0 9.2 5.5 3.3 4.4 4.2 4.6 93.1 88.1 87.5 76.8 93.7 83.8 90.3 78.1 101 90.1 99.4 99.7 100 95.4 95.8 99.0 97.0 87.1 94.5 75.9 10$ 77.2 108 99.4 107 77.2 96.7 86.7 5 3 S 3 3 3 3 3 4 4 4 4 3 3 3 3 3 3 3 3 3 2 3 3 4 4 4 4 $vr Interference problems In elution area of 1242. Measurement based upon only 3 of the 10 normally resolved major peaks. Clean-up techniques 8.1, 8.2, 8.3, 8.4. 8.5. and 8.6 did not Improve the quality of the 1242 chromatogram. If this were an unknown sample. It would be Impossible to qualitatively identify the presence of Aroclor 1242 using ECO. The HED provided an Interference-free chromatogram. HONS 003179 >>>>>>>>>>; TABLE 8 ACCURACY AND PRECISION USING WASTE TRANSFORMER FLUIDS - mp T e Dilution Ratio Oetector Method Clean-up 1260 Spike mg/Kg Av.0 Cone. Found (Precision) Rel. Std. Deviation * (Acturacy) Percent Recovered Number of Qllutloe ECD HED ECO HED ECO HED ECD HED ECD NED ECD HED ECO HED None None 8.1 8.1 8.2 8.2 8.3 8.3 8.4 8.4 8.5 8.5 None None -- -- -- -- .. .. -- -- -- -- -- 27.0 27.0 3 1000:1 ECO None -- 3 " HED " - 3 " ECO " 455 8 " HED " 455 : 1000:1 ECD None -- C " HED " C ECO " 300 C H HED " 300 - dark waste oil - black waste oil with suspended solids - clear waste oil - all samples contained Aroclor 1260 duplicate analyses made at each dilution 22.6 27.0 22.8 29.7 22.4 28.2 22.7 27.8 20.9 30.2 23.8 28.6 45.0 55.2 452 471 875 916 284 300 607 686 3.6 1.7 2.5 1.4 1.0 2.2 1.3 2.8 0.3 4.1 3.3 1.5 0.8 1.2 0.5 2.0 1.2 1.4 3.6 3.9 91 102 - 7* -7 96 7* 99 7* --7 -7 104 7* 114 7 HONS 003180 TABLE 9 Accuracy and Precision and Limit of Detection Data Results of Analyses of Shell Transformer Fluid Spiked with PCBs at S.O and 27 mg/Kg Electron Capture Method (100:1 Dilution) Aroclor 1221 1242 1254 1260 Spike (mg/kg) 5.0 5.0 5.0 5.0 Number of Avg Standard X Recovery MOL Analyses (mg/kg) Deviation (mg/kg) 7 7.5 14 3.8 7 4.1 14 4.7 0.43 0.18 0.08 0.18 150 1.4 76 0.5 82 0.2 94 0.5 Hall Method (100:1 Dilution) Aroclor Spike (mg/kg) Number of Avg Standard X Recovery MOL Analyses (mg/kg) Deviation (mg/kg) 1221 1242 1254 1260 5.0 6 7.5 0.23 150 0.7 5.0 7 5.9 0.17 118 0.5 5.0 6 5.8 0.16 116 0.5 5.0 7 5.4 0.10 108 0.3 Shell Transformer Oil + 27 ppm Aroclor 1260 (100:1 Dilution) Method Spike (mg/kg) 1Number of Analyses Avg (mg/kg) Rel. Std. Deviation X X Recovery Electron Capture Hall 700-A 27 27 14 24.0 7 28.3 .70 2.1 89 105 W= Method Detection Limit at WH confidence that the value is not zero. Note: At these values It would be Impossible to Identify Aroclor patterns with any degree of confidence. 1 mg/Kg appears to be a reasonable MOL. where: MOL t(n-l,.99j S MOL t(n-l,.99) (*) the method detection limit the students' t value appropriate for a 998 confidence level and a standard deviation estimate with n-1 degrees of freedom, standard deviation of the replicate analyses HONS 003181