Differentiation of Aroclors using linear discrimination for environmental samples analyzed by electron capture negative ion chemical ionization mass spectrometry

Journal Article · Mon Mar 15 04:00:00 EST 1993 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00054a021· OSTI ID:6078117

Ma, C Y; Bayne, C K ^[1]

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1. Oak Ridge National Lab., TN (United States)

Environmental samples suspected of containing polychlorinated biphenyls (PCBs) and analyzed by Environmental Protection Agency (EPA) methods frequently contain non-PCB components, such as phinalates, polyaromatic hydrocarbons, or organochlorine pesticides. The presence of these interferences can often obscure the gas chromatographic (GC) patterns and cause problems in differentiating the aroclor types by visual inspection. Because EPA methods require the identification of Aroclor types in order to determine which Aroclor standard should be used for the quantitation calibration, and possibly, to trace the source of PCB occurrences, electron capture negative ion chemical ionization (ECNICI) mass spectrometry was used to provide additional parameters for discriminating PCB congeners from the interferences. In this study, eight Aroclors (i.e., 1016, 1232, 1242, 1248, 1254, 1260, 1262, and 1268) were analyzed by ECNICI for a range of concentration levels. Using selective ion display, the ion abundances of the prominent peaks in the isotopic clusters of molecular ions were measured for eight PCB homologs (Cl) within their GC retention time windows for each sample. Corresponding relative ion abundances from eight Aroclor standards were used as classification training sets. These training sets were used to develop a classification algorithm using standard linear discriminant analysis to classify the PCBs present in an unknown sample(s) as a specific Aroclor. This technique employed a sequential application of two sets of linear discriminant functions to successfully identify known EPA quality control and environmental samples. However, classifications of Aroclor mixtures were less successful. 26 refs., 4 figs., 4 tabs.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6078117
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Vol. 65:6; ISSN 0003-2700; ISSN ANCHAM
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540000 -- Environment-- (1990-)
ALGORITHMS
AROMATICS
CHEMICAL ANALYSIS
CHLORINATED AROMATIC HYDROCARBONS
ELECTRON-CAPTURE DETECTORS
ENVIRONMENTAL MATERIALS
HALOGENATED AROMATIC HYDROCARBONS
IONIZATION
MASS SPECTROSCOPY
MATERIALS
MATHEMATICAL LOGIC
MEASURING INSTRUMENTS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
RADIOMETRIC GAGES
SPECTROSCOPY