MP5 Agrochemicals and Pesticides
Monday, 14 November 2005: 8:00 AM - 5:30 PM in Exhibit Hall

(BAC-1117-466903) Liquid chromatography/tandem mass spectrometry in sulfonylurea herbicide analysis in natural waters: optimization and comparison of electrospray ionization and atmospheric pressure photoionization.

Backus, S¹, Struger, J¹, Batchelor, S¹, Hewitt, L¹, ¹ Environment Canada, Burlington, ON, Canada

ABSTRACT- The applicability of liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the detection of sulfonylurea herbicides in natural waters was examined. Electrospray ionization (ESI) and atmospheric pressure photoionization (APPI) methods were compared with respect to specificity and detection limit. Although both methods proved suitable, LC/APPI MS/MS with a methanol-water gradient including 0.05 % acetic acid was found best for the purpose. Multiple reaction monitoring allowed the determination of sulfonyl ureas at low nanogram per milliliter levels. LC/MS/MS exhibited high sensitivity and specificity for the detection of sulfonyl ureas in natural waters.

Key words: APPI, sulphonyl urea, electrospray