Development and application of hplc-ms/ms method for determination of pesticide traces in water samples

Predmet ovog rada je razvoj, optimizacija, validacija i primena nove, brze i osetljive multirezidualne analitičke metode za određivanje tragova odabranih pesticida, koji pripadaju hemijski različitim grupama, u površinskim, podzemnim i otpadnim vodama. Pri odabiru pesticida prvenstveno je uzeto u obzir koji se najviše koriste u poljoprivrednoj praksi u Srbiji. Prvo je razvijena osetljiva analitička metoda za određivanje odabranih pesticida pomoću tečne hromatografije u sprezi sa tandem masenom spektrometrijom. Posebna pažnja je posvećena optimizaciji metode za pouzdanu maseno-spektrometrijsku detekciju tragova pesticida i razvoju metode potvrde prisustva analita. Zatim je razvijena i optimizovana metoda ekstrakcije na čvrstoj fazi za efikasnu pripremu uzoraka površinskih i podzemnih voda, koja obuhvata istovremenu ekstrakciju i prečišćavanje ekstrakta. Nakon razvoja i validacije metode za pripremu i analizu odabranih pesticida u površinskim i podzemnim vodama, ista je validirana i za uzorke komunalne otpadne vode. Pri validaciji metode određivani su sledeći parametri: prinos, ponovljivost, linearnost, granica detekcije i granica kvantifikacije za sve ispitivane pesticide u svim ispitivanim matricama. Dobre vrednosti prinosa (70%–120%) uz relativnu standardnu devijaciju ± 20% i niske granice detekcije i kvantifikacije postignute su za većinu odabranih pesticida. Potom je razvijena, optimizovana i validirana metoda primenjena na realne uzorke površinskih, podzemnih i otpadnih voda u cilju dobijanja studije o stanju zagađenosti vode najčešće korišćenim pesticidima u našoj zemlji. Istraživanjem je obuhvaćen ceo sliv Dunava u Srbiji sa najvećim pritokama, kao i bunari podzemne vode koji se nalaze u neposrednoj blizini Dunava i pritoka. Uzorci vode prikupljani su u dvanaest kampanja uzorkovanja. Mesta uzorkovanja površinske vode uključivala su poljoprivredna, šumska i gradska područja. Takođe su analizirani i uzorci komunalne otpadne vode Beograda, kao najvećeg grada u našoj zemlji koji bez prethodne obrade otpadne vode direktno ispušta u Dunav i Savu, kao i otpadna voda na ulazu i izlazu iz dva postrojenja za prečišćavanje otpadnih voda. Na osnovu rezultata se može videti uticaj poljoprivrede, i urbane sredine, kao najvećih i najčešćih izvora zagađenja površinskih i podzemnih voda pesticidima.The subject of this thesis is the development, optimization, validation and application of a new, fast and sensitive multiresidual analytical method for determination of selected pesticides, belonging to chemically different groups, in surface and ground water, as well as wastewater. The selection of pesticides was based on their usage in agricultural practice in Serbia. Firstly, sensitive analytical method for the determination of selected pesticides based on liquid chromatography-tandem mass spectrometry was developed. Also, optimization of the method for reliable confirmation of pesticides at trace levels was done. Then, solid-phase extraction method was developed and optimized for efficient preparation of surface and groundwater samples which involves simultaneous extraction and extract purification. Developed and validated method for the sample preparation and analysis of selected pesticides in surface and ground water was validated for municipal wastewater samples. The method was validated for accuracy, reproducibility, linearity, limits of detection and quantification for all investigated pesticides in all tested matrices. Good recoveries (70%–120%) with relative standard deviation ± 20% and low detection and quantification limits have been achieved for the majority of selected pesticides. The developed, optimized and validated method was finally applied to real samples of surface and ground water, as well as wastewater, in order to obtain a study of water contamination with most frequently used pesticides in our country. The study covered the entire Danube basin in Serbia with the largest tributaries, as well as wells of groundwater located near the Danube and tributaries. Water samples were collected in twelve sampling campaigns. Surface water sampling sites included agricultural, forest and urban areas. Municipal wastewater from Belgrade, as the largest city in our country that directly discharges wastewater into the Danube and the Sava without any treatment, was also analyzed, as well as the wastewater at the inlet and the outlet from two wastewater treatment plants. Based on the results, the influence of agriculture and urban environments as the largest and most common sources of pesticide pollution in surface and ground water was determined