New Instruments, New Methods and the Search for Selectivity; Chemical Ionization Mass Spectrometry in Pesticide Metabolite Identification; Negative Ion Electron Capture Chemical Ionization Mass Spectrometry of Fluorinated Pesticide Derivatives; Negative Ion Chemical Ionziation Mass Spectrometry of Toxaphene; Methane-Enhanced Negative Ion Mass Spectra of Hexachlorocyclopentadiene Derivatives; Isomer Specific Analysis of Dioxins and Dibenzofurnas by HRGC/SIM-MS; Determination of Double-bond Position in Conjugated Dienes by Chemical Ionization Mass Spectrometry with Isobutane; Application of Desorption Chemical Ionization Techniques for Analysis of Biologically Active Compounds Isolated from Insects; FD and FAB Mass Spectrometry of Sulfate Conjugants and of Conjugated Metabolites of Pyroquilon; Application of Fast Atom Bombardment Mass Spectrometry to Polar Pesticides; Thermospray HPLC/MS as a Problem-solving Tool for the Analysis of Thermally Labile Herbicides.