title: Critical points in the evaluation of analytical methods based on liquid chromatography separation for the determination of doramectin in different environmental samples.
abstract: In recent years, the number of analytical methods of target compound residues (such as pharmaceuticals) has grown rapidly. Most of them are based on high performance liquid chromatography (HPLC). From the economic point of view, it is usual to apply the conditions of available HPLC methods or to design extraction and chromatographic separation conditions using HPLC and transfer them subsequently to a more sensitive technique like liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). However, if such a transfer is planned, it is important to assess the quality of the newly-designed LC-MS/MS method. The determination of parameters like matrix effects (ME), extraction efficiency (EE) and absolute recovery (AR) is mandatory. These parameters can visualise the weakest step in the analytical method and enable methods based on different techniques to be compared. The aim of this work was to show how quality assessment should be carried out in order to transfer an optimised method from one technique to another. The representative compound used in our investigation was doramectin (DOR), an anthelmintic drug used in veterinary medicine. The quality of the suggested methods for determining this drug in three environmental matrices (water, sediment and fish tissue) using HPLC-UV and LC-MS/MS was evaluated on the basis of known values of absolute recovery (HPLC-UV) and matrix effect, extraction efficiency and absolute recovery (all LC-MS/MS). Finally, the suggested methods for determining DOR in water, sediment and fish tissue based on LC-MS/MS measurements were validated and applied to the analysis of real environmental samples.
authors.affiliation: Department of Environmental Analysis, 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: Department of Environmental Analysis, 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: Department of Environmental Analysis, 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: Department of Environmental Analysis, 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: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland. Electronic address: jolanta.kumirska@ug.edu.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kumirska
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000032:analysis; D017686:Oncorhynchus mykiss; D011044:Poland; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D007559:Ivermectin; C084101:doramectin
keywords: HPLC–UV; LC–MS/MS; Method transferring; Quality assessment