Organochlorine pesticides by negative ion chemical ionization. Brain metabolites of lindane.

A gas chromatographic/mass spectrometric technique for the analysis of organochlorine compounds using negative ion chemical ionization is presented. Detection limits for some compounds (penta- and hexachlorobenzene and p,p'-DDE) are of the order of 60-120 fg injected, while others (lindane, aldrin, etc.) are in the low picogram range (1.0 pg for lindane). The extreme selectivity for chlorine-containing compounds enables the direct analysis of homogenates of biological samples without any extraction or purification step. Metabolic studies can thus be remarkably simplified. Results are presented on the application of this technique to the analysis of lindane metabolites found in rat brain after treatment with this pesticide.