Validation of the determination of antiparasitics and pesticides in activated sludge by the MAE-HPLC-DAD method

U današnje vrijeme, uporaba farmaceutika je u stalnom porastu. Nakon konzumacije farmaceutici iz tijela ljudi i životinja izlaze kao smjesa metabolita i djelomično izvorne aktivne tvari te tako dospijevaju u okoliš. Naime, klasična postrojenja za obradu otpadnih voda ne uklanjaju tako male molekule iz otpadnih voda. Veliki problem su antiparazitici koji imaju vrlo široku primjenu u veterinarskoj medicini. Složene su kemijske strukture, slabo topljivi u vodi, skloni su kristalizaciji te se koncentriraju na sustavima za obradu voda i postojani su u okolišu. S druge strane pesticidi osobito herbicidi u poljoprivredi imaju sve veću primjenu i samom primjenom završavaju u okolišu osobito u obližnjim potocima i rijekama. Pesticidi su uglavnom topljivi u vodi i time lako dospijevaju i u podzemne vode. Štetan utjecaj i farmaceutika i pesticida djelomično je poznat, no utjecaj njihovih razgradnih i transformacijskih produkata koji nastaju tijekom metaboličkih procesa u organizmima ili pod utjecajem fotolize i hidrolize nije uglavnom definiran za te spojeve koji također završavaju u okolišu. Stoga je potrebno pratiti spomenute spojeve i u okolišu, i prije i nakon obrade otpadnih voda primjenom adekvatnih analitičkih metoda. Poseban slučaj je aktivni mulj koji nastaje tijekom obrade otpadnih voda. Naime, veliki broj postrojenja za obradu otpadnih voda koriste konvencionalnu biološku metodu obrade aktivnim muljem. U takvim procesima aktivni mulj postaje izlazni i potencijalno opasni produkt takve obrade kojeg treba zbrinuti. Stoga ga prije zbrinjavanja treba analizirati i utvrditi prisutnost opasnih tvari. U ovom radu pratilo se antiparazitike albendazol, mebendazol i febantel, te pesticid tiakloprid u aktivnom mulju kromatografskom metodom nakon mikrovalne ekstrakcije otapalima. U radu se provela optimizacija postupka mikrovalne ekstrakcije uzoraka te su se određivali validacijski parametri s naglaskom na selektivnost metode.In today's world, the use of pharmaceuticals is on the rise. After consumption, pharmaceuticals are excreted from the bodies of humans and animals as a mixture of metabolites and partially unchanged active substances, thus entering the environment. Traditional wastewater treatment plants do not remove such small molecules from wastewater. A significant problem arises with antiparasitic drugs widely used in veterinary medicine. They have complex chemical structures, are poorly water-soluble, prone to crystallization, and persist in the environment, accumulating in water treatment systems. On the other hand, pesticides, especially herbicides in agriculture, are increasingly used and end up in the environment, particularly in nearby streams and rivers. Pesticides are mostly water-soluble and easily find their way into groundwater. The harmful impact of both pharmaceuticals and pesticides is partially understood, but the influence of their degradation and transformation products that occur during metabolic processes in organisms or under the influence of photolysis and hydrolysis is not well-defined for these compounds, which also end up in the environment. Therefore, it is necessary to monitor these compounds in the environment, both before and after wastewater treatment, using appropriate analytical methods. A special case is the activated sludge generated during wastewater treatment. Many wastewater treatment plants employ conventional biological methods with activated sludge. In such processes, activated sludge becomes an output and potentially hazardous product that needs to be managed. Therefore, it must be analyzed for the presence of dangerous substances before disposal. This study focused on monitoring antiparasitic drugs albendazole, mebendazole, and febantel, as well as the pesticide thiacloprid in activated sludge using chromatographic methods after microwave-assisted solvent extraction. The study involved optimizing the microwave-assisted extraction procedure for samples and determining validation parameters with an emphasis on method selectivity