title: Determination of microcystin-LR in drinking water using UPLC tandem mass spectrometry-matrix effects and measurement.
abstract: A simple detection method using ultra-performance liquid chromatography electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS-MS) coupled with the sample dilution method for determining trace microcystin-LR (MC-LR) in drinking water is presented. The limit of detection (LOD) was 0.04 µg/L and the limit of quantitation (LOQ) was 0.1 µg/L. Water matrix effects of ionic strength, dissolved organic carbon (DOC) and pH were examined. The results indicate that signal detection intensity for MC-LR was significantly suppressed as the ionic strength increased from ultrapure water condition, whereas it increased slightly with solution pH and DOC at low concentrations. However, addition of methanol (MeOH) into the sample was able to counter the signal suppression effects. In this study, dilution of the tap water sample by adding 4% MeOH (v/v) was observed to be adequate to compensate for the signal suppression. The recoveries of the samples fortified with MC-LR (0.2, 1, and 10 µg/L) for three different tap water samples ranged from 84.4% to 112.9%.
authors.affiliation: Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, 13 Yanta Road, Xi'an 710055 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Jinming
authors.initials: J
authors.lastname: Duan
authors.forename: Chaoying
authors.initials: C
authors.lastname: Niu
authors.forename: Naichen
authors.initials: N
authors.lastname: Qiang
authors.forename: Dennis
authors.initials: D
authors.lastname: Mulcahy
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods*; D000458:Cyanobacteria / Q000302:isolation & purification; D060766:Drinking Water / Q000032:analysis*; D057230:Limit of Detection; D008387:Marine Toxins; D000432:Methanol / Q000737:chemistry; D052998:Microcystins / Q000032:analysis*; D009994:Osmolar Concentration; D021241:Spectrometry, Mass, Electrospray Ionization / Q000191:economics / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods*; D014871:Water Microbiology
chemical_list: D001427:Bacterial Toxins; D060766:Drinking Water; D008387:Marine Toxins; D052998:Microcystins; D002244:Carbon; C057862:cyanoginosin LR; D000432:Methanol