Determination of interfering triazine degradation products by gas chromatography-ion trap mass spectrometry

Deethylatrazine (DEA), an atrazine degradation product, has been added to t he US Environmental Protection Agency's Drinking Water Contaminant Candidat e List (CCL). In its gas chromatographic analysis, DEA can coelute with dei sopropylatrazine (DIA), another degradation product. The present work demon strates that the coelution of DEA and DIA can induce a significant (up to s imilar to 50%) positive bias in the DEA determination, when using an ion-tr ap mass spectrometer as the detector. The DIA determination is unaffected b y the coelution within experimental error. This may be explained in terms o f gas-phase ion fragment populations. A correction factor to the observed D EA concentration may be developed based on the measured DIA concentration. Published by Elsevier Science B.V.