title: Determination of metronidazole residues in water, sediment and fish tissue samples.
abstract: Metronidazole (MNZ) is an antibacterial and antiprotozoal drug used in veterinary and human medicine. Its continual entry into the environment and its biological properties may have significant, long-term effects on the stability of ecosystems because MNZ and its metabolites possess mutagenic, carcinogenic and toxic properties. For this reason, the application of MNZ in food-producing species is prohibited in the EU, the USA and other countries. To ensure human food safety and to protect the environment, robust and reliable screening and confirmatory tests capable of the low-level detection of MNZ residues are required. The development of methods for MNZ determination in biological and environmental samples is thus an important analytical task in environmental and food science. This work focuses on the evaluation of a method for determining MNZ in water, sediment and fish tissue samples using liquid chromatography--ion trap mass spectrometry (LC-MS/MS). MNZ was extracted from waters on Strata XC cartridges using solid phase extraction (SPE), and from sediments and fish tissues by solid-liquid extraction (sediment: 15 mL 0.1 M HCl (pH=0.6), 15 min; fish tissue: 15 mL 1% CH3COOH in ACN, 1 min; drying: 5 g MgSO4(anhyd.; 30 s) with SPE purification of the extracts (from sediment: Strata XC cartridge; from fish tissue: Supelco NH2 cartridge). The optimal procedure that we developed was validated in order to confirm its reliability and sensitivity. Matrix effects (ME) were established. Absolute recoveries ranged from 89.3% to 97.2%, and the method detection limits were 3.4 ng L(-1) (water samples), 0.4 ng g(-1) (sediment samples) and 0.3 ng g(-1) (tissue samples). These methods were used to determine MNZ in surface waters, sediments and fish tissues from the Polish River Gościcina; MNZ was found in all these matrices. The highest concentrations in water, sediment and tissue were 136.2 ng L(-1), 12.0 ng g(-1) and 1.5 ng g(-1) respectively. The results confirmed that these methods are suitable for the simultaneous analysis of waters, sediments and fish tissues for the presence of MNZ.
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Wagil
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Maszkowska
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland. Electronic address: a.bialk-bielinska@ug.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Białk-Bielińska
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Magda
authors.initials: M
authors.lastname: Caban
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Stepnowski
authors.affiliation: Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kumirska
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D000981:Antiprotozoal Agents / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods; D019015:Geologic Sediments / Q000032:analysis; D008795:Metronidazole / Q000032:analysis*; D017686:Oncorhynchus mykiss; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D014874:Water Pollutants, Chemical; D008795:Metronidazole
keywords: Fish tissue; Methods of determination; Metronidazole; Sediment; Water