Determination of trace levels of herbicides and their degradation products in surface and ground waters by gas chromatography/ion-trap mass spectrometry

• Published in: Analytica chimica acta 1990, Vol.228 (1), p.69-75
• Main Authors: Pereira, Wilfred E., Rostad, Colleen E., Leiker, Thomas J.
• Format: Article
• Language: English
• Subjects: Analysis methods; Applied sciences; Exact sciences and technology; Freshwater; Natural water pollution; Pollution; Water treatment and pollution
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(00)80480-8

A rapid, specific and highly sensitive method is described for the determination of several commonly used herbicides and their degradation products in surface and ground waters by using gas chromatography/ion-trap mass spectrometry. The compounds included atrazine, and its degradation products desethylatrazine and desisopropylatrazine; simazine; cyanazine; metolachlor; and alachlor and its degradation products, 2-chloro-2',6'-diethylacetanilide, 2-hydroxy-2',6'-diethylacetanilide and 2,6-diethylaniline. The method was applied to surface-water samples collected from 16 different stations along the lower Mississippi River and its major tributaries, and ground-water samples beneath a cornfield in central Nebraska. Average recovery of a surrogate herbicide, terbuthylazine, was greater than 99%. Recoveries of the compounds of interest from river water spiked at environmental levels are also presented. Full-scan mass spectra of these compounds were obtained on 1 ng or less of analyte. Data were collected in the full-scan acquisition mode. Quantitation was based on a single characteristic ion for each compound. The detection limit was 60 pg with a signal-to-noise ratio of greater than 10:1.