CHARACTERIZATION OF TECHNICAL TOXAPHENE USING COMBINED HIGHPERFORMANCE LIQUID CHROMATOGRAPHY-GAS CHROMATOGRAPHY-ELECTRON CAPTURE NEGATIVE IONIZATION MASS-SPECTROMETRY TECHNIQUES

More than 300 congeners in technical toxaphene were distinguished by combined HPLC-GC/electron capture negative ionization mass spectrometry (ECNIMS) techniques. Good separation of most congeners on a 60-m DB-5 GC column was achieved when the mixture was pre-separated into five fractions by silica gel HPLC. ECNI spectra of high chlorinated congeners were dominated by M - Cl while both M and M - Cl ions were important in low chlorinated ones. Other ions such as M - 3Cl, M - Cl - HCl and M - Cl - 2HCl can be used to distinguish congeners. Peaks referred to as T2 and T12 in the environment by many authors coelute with several congeners in toxaphene. The 2,5-exo-3,6-endo tetrachloro partial structure existing in both T2 and T12 may be responsible for their persistency in living systems. Results from EI-SIM mode indicated many other low chlorinated congeners not detectable by ECNI in the mixture.