WP6 Emerging Pollutants
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(BAC-1117-722482) Determination of nine sulfonamides in natural waters by high performance liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry.

Backus, S.¹, Struger, J.¹, Bennie, D.¹, Palabrica, V.¹, Hewitt, M.¹, ¹ Environment Canada, Burlington, ON, Canada

ABSTRACT- A robust and sensitive, high performance liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (HPLC/APPI) method for the determination of residues of sulfonamides in natural waters is described. The sulfonamides are extracted from filtered water using graphitized non-porous carbon. Detection of the analytes was achieved by positive photoionization (APPI) followed by multiple reaction monitoring. For each sulfonamide the collisional decomposition of the protonated molecule to a common, abundant fragment ion was monitored. The method has been validated for sulfisoxazole, sulfathiazole, sulfapyridine, sulfamethoxazole, sulfamethiazole, sulfamethazine, sulfachloropyridazine, sulfacetamide, and sulfamethoxypyridazine. The method was applied to the determination of sulfonamides in natural waters collected in a number of watersheds in southern Ontario. Preliminary data show that six of the sulfonamides were detected regularly above the analytical detection limit. The procedure provides a rapid, reliable and sensitive method for the determination of residues of sulfonamides in natural waters.

Key words: sulfonamides, surface water, APPI, LC/MS/MS