Characterization of technical toxaphene using combined high-performance liquid chromatography-gas chromatography-electron capture negative ionization mass spectrometry techniques

Abstract

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.