title: Development and validation of a liquid chromatography-tandem mass spectrometry assay for the simultaneous quantitation of microcystin-RR and its metabolites in fish liver.
abstract: A novel method for identification and quantification of microcystin-RR (MC-RR) and its metabolites (MC-RR-GSH and MC-RR-Cys) in the fish liver was developed and validated. These analytes were simultaneously extracted from fish liver using water containing EDTA with 5% acetic acid, followed by a mixed-mode cation-exchange SPE (Oasis MCX) and subsequently determined by liquid chromatography-electrospray ionization ion trap mass spectrometry (LC-ESI-ITMS). Extraction parameters including volume and pH of eluting solvents, were optimized. Best recoveries were obtained by using 10 mL of 15% ammonia solution in methanol. The mean recoveries at three concentrations (0.2, 1.0, and 5.0 microg g(-1) dry weight [DW]) for MC-RR, MC-RR-GSH and MC-RR-Cys were 93.6-99%, 68.1-73.6% and 90.0-95.2%, respectively. Method detection limit (MDL) were 4, 7 and 5 ng g(-1) DW for MC-RR, MC-RR-GSH and MC-RR-Cys, respectively. Limits of quantification (LOQs) for MC-RR, MC-RR-GSH and MC-RR-Cys were calculated to be 10, 18 and 13 ng g(-1) DW, respectively. Finally, this method was successfully applied to the identification and quantification of MC-RR, MC-RR-GSH and MC-RR-Cys in the liver of bighead carp with acute exposure of MCs.
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China.
authors.forename: Laiyan
authors.initials: L
authors.lastname: Wu
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Dawen
authors.initials: D
authors.lastname: Zhang
authors.forename: Gaodao
authors.initials: G
authors.lastname: Liang
mesh_terms: D000818:Animals; D002347:Carps / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods*; D004784:Environmental Monitoring; D057230:Limit of Detection; D008099:Liver / Q000378:metabolism*; D008387:Marine Toxins; D000432:Methanol / Q000737:chemistry; D052998:Microcystins / Q000032:analysis* / Q000737:chemistry; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors
chemical_list: D008387:Marine Toxins; D052998:Microcystins; C063855:microcystin RR; D000432:Methanol