English Abstract In this work, the utility of gaschromatography-ion
mass-spectrometry for the screening on pesticides in water has been studied.
Essential for screening purposes is that the presence of compounds of
interest can be shown by the method in a relatively rapid and simple but
reliable way. The present study has been restricted to the group of
organophosphoreus pesticides of which approximately 75 compounds are used in
the Netherlands and hence can occur in the environment. Of 62 out of 65
pesticides examined, electron impact and chemical ionization spectra have
been obtained and relative retention indices (relative to parathion) have
been determined. Detection limits ranged between 50- 500 pg on column for
compounds having good GC properties. 500-5000 pg were needed for some
compounds having poor GC properties.