EPA-OGWDW/TSC: 1668a (Water):  Chlorinated Biphenyls in Aqueous Samples by HRGC/HRMS

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
 Chlorinated Biphenyl Congeners in Water, Soil, Sediment, Biosolids and Tissue by HRGC/HRMS
Current Revision
Revision A, December 1999
Media
 WATER
Instrumentation
 Gas Chromatography with Mass Spectrometry Detection
Method Subcategory
 Organic
Method Source
  EPA-OGWDW/TSC
Citation
  Method 1668, Revision A: Chlorinated Biphenyl Congeners in Water, Soil, Sediment, and Tissue by HRGC/HRMS (EPA 821-R-00-002)
Brief Method Summary
 Samples are spiked with isotopically labeled analogs of target analytes, and extracted according to a procedure specified for the matrix being analyzed. After extraction, a labeled cleanup standard is spiked into the extract which is then cleaned up using appropriate chromatographic procedures (e.g., gel permeation). After cleanup, the extract is concentrated. 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. The analytes are separated by the GC and detected by a high-resolution (>=10,000) mass spectrometer (HRGC-HRMS). Two exact mass/charge ratios (m/z's) are monitored at each level of chlorination (LOC) throughout a pre-determined retention time window. An individual CB congener is identified by comparing the GC retention time and ion-abundance ratio of two exact m/z's with the corresponding retention time of an authentic standard and the theoretical or acquired ion-abundance ratio of the two exact m/z's. Quantitative analysis is performed in one of two ways specified in the method using selected ion current profile (SICP) areas.
Scope and Application
 This method determines chlorinated biphenyl congeners (CBs) in water, soil, sediment, biosolids, tissue, and other sample matrices by high resolution gas chromatography/high resolution mass spectrometry.
Applicable Concentration Range
 0.01-20 ng/L
Interferences
 (A) Contamination: Glassware must be thoroughly cleaned and all materials used must be demonstrated to be free of contamination by running reference matrix blanks. Specific seletion of reagents and purification of solvents by distillation in all-glass systems may be required to remove contaminants. Also, samples should be prepared in an area free from air contaminated with target analytes (e.g., glove box)

(B) Co-extracted interferences: The most frequently encountered interferences are chlorinated dioxins and dibenzofurans, methoxy biphenyls, hydroxydiphenyl ethers, benzylphenyl ethers, brominated diphenyl ethers, polynuclear aromatics, polychlorinated naphthalenes, and pesticides. Because very low levels of chlorinated biphenyls (CBs) are measured by the method, the elimination of interferences is essential. The cleanup steps given in Section 13 of the method can be used to reduce or eliminate these interferences, permitting reliable determination of the CBs.

(C) Lipids in tissue: The natural lipid content of tissue can interfere in the analysis of tissue samples for the CBs. Lipids must be removed by an anthropogenic isolation column procedure, followed by the gel permeation chromatography procedure as described in the method. Florisil is recommended as an additional cleanup step.
Quality Control Requirements
 The minimum quality control (QC) requirements consist of an initial demonstration of laboratory capability, analysis of samples spiked with labeled compounds to evaluate and document data quality, and analysis of standards and blanks as tests of continued performance. Laboratory performance is compared to established performance criteria to determine if the results of analyses meet the performance characteristics of the Method. If the Method is to be applied to sample matrix other than water (e.g., soils, filter cake, compost, tissue) the most appropriate alternate reference matrix is substituted for the reagent water matrix in all performance tests.
Sample Handling
 Collect samples in amber glass containers following conventional sampling practices. Preservation requirements vary with the sample matrix being analyzed.

Aqueous samples: Keep in the dark at 0-4oC from the time of collection until receipt at the laboratory. If the sample will be frozen, allow room for expansion. Store in the dark at 0-4oC.

Non-aqueous samples (non-tissue): Maintain solid, semi-solid, oily, and mixed-phase samples in the dark at <4oC from the time of collection until receipt at the laboratory. Store solid, semi-solid, oily, and mixed-phase samples in the dark at < -10 oC.

Tissue samples (e.g., fish): Collect sample, wrap in aluminum foil, and maintain at <4 oC from the time of collection until receipt at the laboratory, to a maximum time of 24 hours. If a longer transport time is necessary, freeze the sample. Ideally, samples should be frozen upon collection and shipped to the laboratory under dry ice. Freeze tissue samples upon receipt at the laboratory and maintain in the dark at < -10oC until prepared. Maintain unused sample in the dark at < -10oC.
Maximum Holding Time
 1 year
Relative Cost
 Greater than $400
Sample Preparation Methods
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