EPA Method A in the EPA methods list database. View all EPA methods. EPA Method A: Chlorinated Biphenyl. Congeners by HRGC/HRMS. Horizon Technology, Inc., Salem, NH. Horizon Technology, Inc., 45 Northwestern Dr. Ecology may require or allow the use of the most current accepted revision of EPA Method (USEPA, ) at contaminated sites, instead.
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Unlike the plots of relative variability for tissue and wastewater samples, this plot does not suggest a strong relationship e;a variability and concentration. The instructions were based on procedures given in Method A.
If a GC column or column system alternate to the SPB-octyl column is used, a similar minimum retention time specification must be established for the alternate column or column systems so that interferences that may be encountered in environmental samples will be resolved from the analytes of interest. Repeat the bottle rinsing and elution step with another 20 mL of methylene chloride. Archive both the concentrated solvent and the solvent in the catch flask for a contamination check if necessary.
Cap and shake the sample and QC aliquots to mix thoroughly, and proceed to Section Each laboratory that uses this Method must demonstrate the ability to generate acceptable results using the procedure in Section 9.
The exact volumes of solvents will need to be determined for each batch of Florisil. Insert a glass-wool plug on top of the bed to hold the adsorbent in place. The kiln or furnace should be vented to prevent laboratory contamination by CB vapors. Labeled level of chlorination LOC quantitation congener 6.
Disclaimer Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Section Safety Instrument internal standard 8. Following calibration, flush the injection system with solvent to ensure that residual CBs are removed from the system.
If, however, any individual RSD exceeds the precision limit or any individual X falls outside the range for recovery, system performance is unacceptable for that compound. The extract is concentrated for cleanup. Laboratory 4 reported difficulties with the cleanup of both the biosolids samples.
Toluene is difficult to concentrate using the K-D technique unless a water bath fed by a steam generator is used. The laboratory reported unsuccessful use of an acid-base wash dpa, and two rounds of silica gel cleanup. This test is described in Section 9. Computations of relative standard deviation RSD are be used to test calibration linearity. The participant and sample processing laboratories are listed in Table If the amount of material in the extract will overload the column, split the extract into fractions and combine 16688a fractions after elution from the column.
In this case, alternate extraction and cleanup procedures in this Method or an alternate GC column must be employed to resolve the interference. The sample processing laboratory was required to perform background and homogeneity analyses of both the biosolids and tissue matrices.
Shake for 2 minutes with periodic venting into a hood. Apply power to the heating mantle to begin re-fluxing.
Quality control QC acceptance criteria for initial precision and recovery, ongoing precision and recovery, and labeled compound recovery from real world samples are in Table of this report. Allow the organic layer to separate from the aqueous phase for a minimum of 10 minutes. Native PCB standards are available from several suppliers.
Isomer specificity for certain of the CB congeners is achieved using GC columns that resolve these congeners. Each group or descriptor must be monitored in succession as a function of GC retention time to ensure that the CBs of interest are detected. Other quantitation references and procedures may be used provided that the results produced are as accurate as results produced by the quantitation references and procedures described in this Section.
The natural lipid content of tissue can interfere in the analysis of tissue samples for the CBs. The method of reducing particle size to less than 1 mm is matrix-dependent. Laboratory performance is compared to established performance criteria to determine if the results of analyses meet the performance characteristics of the Method.
Reference standards that can be used to determine the accuracy of standard solutions are available from several vendors.
During analytical operations that may give rise to aerosols or dusts, personnel should wear respirators equipped with activated carbon filters.
Immediately prior to injection, labeled injection internal standards are added to each extract and an aliquot of the extract is injected into the gas chromatograph GC. The residue content of the extract may be obtained gravimetrically by evaporating the solvent from a iL aliquot.
The estimated minimum levels EMLs in Table 2 are based on common laboratory contamination levels. If overseas laboratories are included in the study, biosolids and tissues may be freeze dried so that they can be shipped without concern that ice may melt during extended transit times.
Reduce the volume to approximately iL. Dilute the Labeled cleanup standard stock solution Section 7. The column specified in this Method is designed to handle a maximum of 0.
Following a review of the background results by SCC, EPA defined the spiking levels, and provided the sample processing laboratory with detailed instructions to divide the unspiked POTW matrix into the required number of aliquots and spike each aliquot separately rather than spiking a bulk volume of wastewater and then subdividing the spiked sample into replicate aliquots to the epq concentrations.
The acid 16668a gel Section 7.
Trichlorobiphenyls, Total Report List. Start MS data collection after the solvent peak elutes. To offset costs to the laboratories, EPA 1668aa each laboratory with a set of analytical standards necessary to identify and measure the PCB congeners targeted by Method A.
Table lists the numbers of wastewater, biosolids, and tissue samples that were prepared for distribution to the 14 participant laboratories.