Prisustvo tragova lekova i pesticida u rečnim sedimentima i vodi i njihova sorpcija na materijalu akvifera

Abstract

Predmet ove studije je razvoj i optimizacija novih metoda za pripremu uzoraka vode i sedimenata i istovremenu analizu prisustva tragova lekova i pesticida u njima, kao i razvoj i optimizacija metode pripreme uzoraka sedimenata za ispitivanje sorpcije odabranih lekova i pesticida. Metode pripreme uzoraka zasnovane su na ekstrakciji na čvrstoj fazi (SPE, eng. Solid-Phase Extraction), u slučaju pripreme uzoraka vode i ultrazvučnoj ekstrakciji rastvaračem (USE, eng. Ultrasonic Solvent Extraction), u slučaju pripreme uzoraka sedimenata. Metoda analize zasnovana je na tečnoj hromatografiji u kombinaciji sa tandem masenom spektrometrijom (HPLC-MS/MS, eng. High Performance Liquid Chromatography Tandem Mass Spectrometry). Za najveći broj ispitivanih jedinjenja postignut je visok prinos. Primena optimizovanih metoda za pripremu i analizu uzoraka površinske i podzemne vode i rečnih sedimenata izvršena je na velikom broju realnih uzoraka reke Dunav i njenih najvećih pritoka na teritoriji Republike Srbije. U cilju sagledavanja stanja reke Dunav i eventualnog uticaja pritoka na njen kvalitet u pogledu prisustva određenih lekova i pesticida, uzorci su uzeti na ključnim tačkama dela toka reke Dunav u Srbiji i na lokacijama na njenim pritokama pozicioniranim neposredno pre ulivanja. Rezultati su pokazali da se određeni lekovi i pesticidi nalaze samo u površinskim i/ili podzemnim vodama, dok se neki od njih nalaze samo u sedimentima. Zabeleženo je da se jedan analit na dve lokacije nalazi i u površinskoj vodi i u sedimentu, ali nije zabeležen slučaj da se neki od ispitivanih analita nalazi u sedimentu i u njemu odgovarajućoj podzemnoj vodi, kao ni to da se nalazi u sva tri ispitivana medijuma na istoj lokaciji. U cilju daljeg razmatranja eventualnih razloga zbog kojih su neki od ispitivanih lekova i pesticida najčešće nalaženi u površinskoj vodi, bili vezani za sediment ili ostvarili prolaz do podzemnih voda, na sedimentima sa odabranih lokacija ispitivana je sorpcija lekova i pesticida. Jedan od uzoraka uzet je iz akvifera reke Save, zbog specifičnosti njegovog profila i činjenice da se nalazi u okviru vodozahvata grada Beograda. Preostala tri uzorka sedimenata uzeta su iz Dunava i profila akvifera drenažnog sistema Kovin-Dubovac, sa različitih dubina, zbog činjenice da je najveći broj jedinjenja nađenih u podzemnim vodama zabeležen baš na ovom prostoru kao i činjenice da se radi o akviferu profila sličnog profilima preostalih akvifera čiji su uzorci rečnih sedimenata, površinske i podzemne vode prethodno analizirani na prisustvo odabranih lekova i pesticida...

The subject of this study is the development and optimization of new methods for preparation of water and sediments samples and simultaneous analysis of trace levels of pharmaceuticals and pesticides in them, as well as the development and optimization of the method for preparation and testing of sediment samples on sorption of selected pharmaceuticals and pesticides. Methods of samples preparation are based on solid-phase extraction (SPE), in the case of water samples preparation, and ultrasonic solvent extraction (USE), in the case of sediment samples preparation. The analysis method is based on liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). For the most of the tested compounds a high recovery was achieved. The application of optimized methods for the preparation and analyses of surface and ground water as well as river sediments was performed on a large number of real samples from the Danube River and its major tributaries on the territory of the Republic of Serbia. With the goal to overview the condition of the Danube River and the potential impact of tributaries on its quality in terms of presence of certain pharmaceuticals and pesticides, the samples were taken at key points of the flow of the Danube River in Serbia and at locations of its tributaries positioned just before the confluence. Results have shown that certain pharmaceuticals and pesticides are found only in surface and/or ground waters, while some of them are found only in sediments. It was noted that one analyte is found in the surface water and corresponding sediment at two locations but none of the analytes have been found neither in the sediment and its corresponding ground water, nor in all three tested media at the same location. In order to estimate the reasons for occurence of some of the tested pharmaceuticals and pesticides in surface or ground water or river sediment, optimized methods were applied on the sediments from chosen locations for testing sorption of pharmaceuticals and pesticides. One of the sediment samples was taken from the aquifer of the Sava River, due to its specific profile and the fact that it is located within the water intake of the city of Belgrade. The remaining three samples were taken from the Danube aquifer of the drainage system Kovin-Dubovac, from different depths, given the fact that the largest number of compounds found in the ground waters were noted exactly in this area. This aquifer has a similar profile to the profiles of the remaining aquifers where surface water, ground water and river sediments were previously analyzed for selected pharmaceuticals and pesticides...