Analysis of divalent metal dialkyldithiocarbamates by gas chromatography and mass spectrometry

The influence of various gas chromatographic supports, coated with SE-30 as stationary phase, on the qualitative and quantitative analysis of Ni(II) and Zn(II) dithiocarbamates was investigated. Retention indices were correlated with the structures of the compounds studied. Cu(II), Co(II) and Cd(II) dialkyldithiocarbamates decomposed during analysis under the applied conditions. Special emphasis was given to the quantitative analysis of Ni(II) and Zn(II) bis(N,N-dialkyldithiocarbamates). Basic conditions were established for the separation of Ni(II) bis(N,N-dialkyldithiocarbamates) on glass capillary columns coated with polydimethylsiloxane stationary phases (OV-101 and SE-30). The main problem in the successful analysis of these compounds in glass capillary columns was found to be adsorption on the column wall. Electron-impact positive-ion mass spectra of Ni(II) and Zn(II) bis(N,N-dialkyldithiocarbamates) are discussed in detail. From the mass spectra of these compounds, general fragmentation pathways were derived. All of the dithiocarbamates studied showed molecular ions, the intensity of which decreased with increasing size of the alkyl substituent