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

ABSTRACT

A 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.

KEYWORDS:

• Organophosphate pesticides
• GC-MS/MS
• micro-extraction
• sea water
• surface water

Acknowledgements

This work was funded by the State Office for Agriculture, Food Safety and Fisheries Rostock and the Leibniz Institute for Baltic Sea Research Warnemünde and was performed within the scope of the Leibniz ScienceCampus Phosphorous Research Rostock. The authors are grateful to Ines Dahse, Anke Wulf, Brigitte Ewald, Kathrin Fuchs and Bernd Kraemer for technical support during method optimization and validation.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Funding

This work was funded by the State Office for Agriculture, Food Safety and Fisheries Rostock and the Leibniz Institute for Baltic Sea Research Warnemünde.