Medium to highly polar pesticides in seawater: Analysis and fate in coastal areas of Catalonia (NE Spain)

Pollution has been less investigated in marine and coastal environments than in inland waters. The low levels at which pollutants are expected to be present in seawater calls for the use of reliable and high sensitivity analytical methodologies. In this context, this work presents the optimization and validation of an analytical method to determine 26 medium to highly polar pesticides in seawater based on solid phase extraction and liquid chromatography-tandem mass spectrometry detection. The developed methodology was linear, accurate (relative recoveries within 80–120% for most analytes), repeatable (relative standard deviations <18% for most analytes), and sensitive (limits of determination <1 ng/L for 89% of the compounds). The use of isotopically labeled compounds as surrogate standards compensated for low analyte recoveries and matrix effects. The method was applied to the analysis of seawater samples collected along the coastline of Catalonia (NE Spain). Overall, total pesticide loads were higher inside the marinas than outside. The booster biocides diuron and irgarol used in antifouling paintings and different triazine pesticides were the most abundant compounds. Irgarol was present above the maximum allowable concentration set in European regulations in 70% of the samples collected inside the marinas. A different pesticide pollution pattern, with MCPA and bentazone presenting the highest concentrations, was observed at the Ebro Delta area due to the impact of the agricultural activities carried out there. To the authors’ knowledge, 4 out of the 26 target pesticides, namely, chlorfenvinphos, fenthion oxon, fenthion sulfone, and fenthion sulfoxide, have not been previously investigated in seawater. © 2018 Elsevier Ltd

This work has been financially supported by the EU FP7 through the SOLUTIONS project (FP7-ENV-2013, No. 603437), by the Ministry of Science, Innovation and Universities through the PLAS-MED project (CTM2017-89701C3-R), and by the Generalitat de Catalunya (Consolidated Research Group 2017 SGR 01404 - Water and Soil Quality Unit). Thanks to the Swedish University of Agricultural Sciences for its support through the August T Larsson Guest Researcher Programme. The authors would also like to express their gratitude to Cristina Bosch, Gabriella Schirinzi, Josep Sanchís, Mar Olmos and Samuel Jimenez for their assistance with sampling, and to Simon Monllor for his assistance with sample processing.

Peer reviewed