Determination of organophosphate pesticides in sea and surface water with ultrasound-assisted dispersive liquid–liquid micro-extraction coupled to GC-MS/MS analysis

Abstract

ABSTRACTA sensitive enrichment method for the detection and quantification of 20 organophosphate pesticides in sea water and surface water was improved and validated. The compounds were extracted using ultrasound-assisted dispersive liquid–liquid microextraction and were analysed with an optimised Gas Chromatography - Tandem Quadrupole Mass Spectrometry (GC-MS/MS) method. Calibrations and validations were conducted for spiked local pond and Baltic Sea water. Recoveries of the organophosphate compounds from the different matrices ranged from about 25% to 70% and from 30% to 130% for pond and sea water, respectively. Obtained limit of detection (LoD) for both matrices was about 3 ng L−1 and the limit of quantification (k = 3) was 12 and 7 ng L−1 for pond and sea water, respectively. Valid extractability at the LoD level could be proven.