Method for Analysis of Polybrominated Biphenyls by Gas Chromatography Mass Spectrometry? Mitchell D. Erickson, Leonid Kelner,$ Joan T. Bursey, David Rosenthal, Ruth A. Zweidinger and Ed0 D. Pellizzari zyxwvutsrq Analytical Sciences Division, Chemistry and Life Sciences Group, Research Triangle Institute, Post Office Box 12194, Research Triangle Park, North Carolina 27709, USA Gas chromatography using a short packed column (45 cm, 0.2 cm i.d., 2'% OV-101 on Gas-Chrom Q) with mass spectrometric detection in the selected ion monitoring mode has been found satisfactory for the analysis of lower as well as higher polybrominated biphenyls. Acceptable sensitivity (el ng) may be achieved for this method by focusing selectively at either the low zyxwvutsrq (m/z 20-600) or the high zyxwvu (m/z 600-1000) range of the quadrupole filter (low range for mono- through hexabromobiphenyl, high range for hexa- through decabromobiphenyl). A tuning technique has been developed for low range and high range polybrominated biphenyls using the ion abundances of perfluorotributylamine as a standard. Standard ions for the quantitation of mono- through decabromo- biphenyls were selected and validated. The technique was applied to the analysis of a variety of environmental samples. INTRODUCTION Polybrominated biphenyls (PBBs) have been used pri- marily as fire retardants. A mixture of PBB isomers has been marketed as Firemaster BP-6 or Firemaster FF- 1. Interest in the toxicity of PBBs was first generated when Firemaster BP-6 was accidentally mixed with livestock feed in place of the supplement magnesium oxide (trade name-Nutrimaster), resulting in contamination of feed as high as 13 500 parts per million of PBBs.'-~ It was shown that animals which ingested this contaminated feed attained PBB levels as high as 300ppm in fat.4 Approximately 30 Michigan dairy farms were contaminated and a number of analytical methods for PBBs as applied to feeds,5 dairy products,6 soils73s as well as human plasma, animal feces, milk and bile' were developed. Data on productiofi, pollution from manufacture, human exposure, and health effects of PBBs have been reviewed." A wide variety of toxic effects of PBBs on animals after single oral doses as well as after chronic administration were Toxic effects of PBBs on humans are still considered controversial, but certain health effects have been described €or Michigan and New York residents.") As a result of these findings, the manufacture of PBBs in the United States has now been discontinued, as has their use. Nevertheless, the presence of PBBs in the environment still constitutes a significant public health hazard due to their environ- mental persistence and their long biological half-life. Thus, analytical methods for qualitative and quan- titative determinations of PBBs need to be developed. There are very limited data on gas chromatographic zyxwvu ? Abbreviations: PBB = polybrominated biphenyl; PBBO = poly- brominated biphenyl ether. $ Present address: Biomedical Engineering and Instrumentation Branch, Building 13, Room 3W13, National Institutes of Health, Bethesda, Maryland 20205, USA. mass spectrometric (GCMS) analysis of the higher members of the series (Br,-Brlo) of PBBs by GCMS. Recent work published by Hass et zyxw a1.l2 deals with the chemical and toxicological evaluation of Firemaster BP- 6 and describes the GCMS method for the analysis of mono- through hexabromobiphenyl. The lack of data on higher PBBs is due in part to difficulties of detection of these compounds by GCMS, especially when using quadrupole instruments. The objectives of this work were to find suitable GC conditions, to define the MS quadrupole characteristics for the analysis of PBBs in environmental samples, and to demonstrate the analysis with real environmental samples. EXPERIMENTAL Materials Toluene (Burdick and Jackson, Muskegan, Michigan) was redistilled prior to use. Polybrominated biphenyls (4-bromobiphenyl, 4,4'-dibromobiphenyl, 2,2',5-tri- bromobiphenyi, zyxw 2,2',5,5'-tetrabromobiphenyl, 2,2',4,5,6-pentabromobiphenyl, 2,2',4,4',5,5'-hexa- bromobiphenyl, 2,2',3,3',5,5',6,6'-octabromobiphenyl, and decabromobiphenyl), and octachloronaphthalene (external standard) were purchased from RFR Corporation, Hope, Rhode Island. Standard solutions of PBBs were prepared in toluene at concentrations vary- ing from 2-500 pg pL-' of each component. Gas chromatography of PBBs Gas chromatographic conditions necessary to separate lower and higher biphenyls were determined experi- mentally. During the preliminary work it was found that @ Heyden & Son Ltd, 1980 CCC-0306-042X/80/0007-0099$03.00 EIOMEDICAL MASS SPECTROMETRY, VOL. 7, NO. 3, 1980 zyx 99