HIGH-RESOLUTION SELECTIVE ION MONITORING GC-MS DETERMINATION OF TOXAPHENE IN GREAT-LAKES FISH

Toxaphene is a broad spectrum insecticide comprised of over 650 polych lorinated bornane congeners. As with PCBs, the complex nature of this mixture makes its quantitation very difficult. Current methods for the quantitation of toxaphene are GC-ECD or electron capture negative ion ization (ECNI) mass spectrometry. An alternative GC-MS method was deve loped in this laboratory whereby toxaphene congeners are selectively i dentified by high resolution selective ion monitoring GC-MS (HRSIM GC- MS) of ions present in the EI spectrum of all congeners. Selective ion monitoring of these ions, at masses 158.9768 and 160.9739, is not sub ject to interference from 69 other organochlorines which may be presen t in the matrix. Using this HRSIM GC-MS method, toxaphene levels in Gr eat Lakes fish were measured.