Multiresidue method for the analysis of five antifouling agents in marine and coastal waters by gas chromatography-mass spectrometry with large-volume injection

A simple multiresidue method has been developed for the determination of fi ve pesticides, commonly used as active ingredients in antifouling paints, i n seawater samples. The pesticides studied were: chlorothalonil (2,4,5,6-te trachloro-isophthalonitrile), dichlofluanid (N-dimethyl-N-phenylsulphamide) , Sea-Nine 211 (4,5-dichloro-2-n-octyl-4-isothazolin-3one), Irgarol 1051 (2 -methylthio-4-tert.-butylamino-6-cyclopropylamino-s-triazine) and TCMTB (2- thiocyanomethylthiobenzothiazole). The analytes were extracted from 200 ml water samples, using solid-phase extraction. A copolymer with hydrophilic-l ipophilic balance was used as sorbent yielding good recoveries (82-95%) for most compounds except dichlofluanid and Sea-Nine 211 (<60%). Large volume injection (10 mu l) gas chromatography and electron impact ionization MS (s elected ion monitoring mode) detection enabled these compounds to be identi fied and quantified at the 1.2-3.0 ng/l level. Analysis of samples performe d in three marinas in Almeria (Spain) revealed the presence of Irgarol 1051 in all the cases, at concentration levels between 25 and 450 ng/l. (C) 200 0 Elsevier Science B.V. All rights reserved.