Abstract
German As part of our OPENTOX project, we evaluated the incidence and mass concentrations of multiclass pesticide residues in 23 river/stream water samples collected in urban and agricultural areas of northwest Croatia at various points of the pesticide application season in 2015. The study included 16 compounds of five herbicide classes and seven compounds of three insecticide classes. Pesticide residues were accumulated from water by solid-phase extraction and analysed using high performance liquid chromatography with UV-diode array detection and/or gas chromatography-mass spectrometry. Herbicide residues were more common than the insecticide ones, and, as expected, they peaked in the middle of the application season. Metolachlor showed the highest concentrations and was found in 91 % of all samples, followed by terbuthylazine, found in 70 % of the samples. The highest total mass concentration of detected pesticides was measured in the water samples of the Krapina (3992 ng/L) and Sutla (3455 ng/L) collected in rural areas with intensive agriculture. Our findings strongly speak in favour of continued monitoring of surface waters and possibly extending the list of priority water pollutants. U sklopu našega projekta OPENTOX odredili smo masene koncentracije ostataka pesticida i njihovu učestalost u 23 uzorka vode rijeka/potoka u gradskim i ruralnim dijelovima sjeverozapadne Hrvatske, prikupljenih 2015. tijekom sezone njihove primjene. Istraživanje je obuhvatilo 16 spojeva iz pet različitih klasa herbicida i sedam spojeva iz triju klasa insekticida. Ostaci pesticida akumulirani su iz vode postupkom ekstrakcije na čvrstoj fazi i analizirani tekućinskom kromatografijom visoke djelotvornosti uz UV-detektor s nizom dioda ili vezanim sustavom plinske kromatografije i spektrometrije masa. Češće su detektirani ostatci herbicida nego insekticida, a najviše su koncentracije bile sredinom sezone njihove primjene. Metolaklor je određen u najvišoj koncentraciji i u najvećem broju uzoraka (91 %), a slijedio ga je terbutilazin, koji je nađen u 70 % uzoraka. Najviša ukupna razina određivanih pesticida bila je u uzorcima rijeka Krapine (3992 ng/L) i Sutle (3455 ng/L), koji su bili prikupljeni u ruralnom području s intenzivnom poljoprivredom. Rezultati našega istraživanja govore u prilog potrebi ne samo za kontinuiranim monitoringom pesticida u površinskim vodama nego i za proširenjem liste prioritetnih zagađivala.