ABSTRACT
The incidence of cyanobacterial harmful algal blooms (CHABs) and their potentially toxic secondary metabolites is increasing in Italy and worldwide and several studies demonstrated that the climate change may be playing a role. The method described in this work allows to detect simultaneously 21 cyanotoxins of different classes (including 12 Microcystins, 5 Microginins, 2 Cyanopeptolins, and 2 Anabaenopeptins) in water samples for human consumption by an Ultra Performance Liquid Chromatography coupled with a Q-TOF mass spectrometer. Water samples were freezed, filtered, spiked with Nodularin used as internal standard (I.S.) and then extracted with a SPE Carboghaph 4 cartridge. The extracted sample were analysed injecting 10 µL into the UPLC-HRMS/MS system: the chromatographic separation was obtained using acetonitrile and water as mobile phases, both containing 10 mM formic acid, and a UPLC C18 column, acquiring the experiments in positive ionization and Sensitivity Mode. The described method allows to separate and detect all the selected analytes in short time of analysis (16 minutes) with a good resolution for all the analytes.â¢simultaneous determination of 21 cyanotoxins belonging to different classes in water sampleâ¢low injection volumeâ¢short time of analysis.
ABSTRACT
The presence of cyanobacteria and their toxins in water used as drinking water or for recreational purposes may represent a risk for human health. This work describes the development of an advanced analytical method for simultaneous determination of 21 cyanotoxins (including Microcystins, Cyanopeptolins, Anabaenopeptins and Microginins) in drinking water based on Ultra Performance Liquid Chromatography coupled with a Q-TOF mass spectrometer. Water samples, spiked with Nodularin as internal standard at 1 µg/L, were extracted using Carbograph 4 SPE cartridge and 10 µL of the extracted sample were injected into the UPLC-HRMS/MS system. Analytes separation was obtained using a UPLC C18 column, acetonitrile and water as mobile phases, both containing 10 mM formic acid, and operating in positive ionization mode and sensitivity mode. The method has been proven to be robust, precise and accurate with recovery percentages above 85% and with relative standard deviations ≤16% and LODs between 0.002 and 0.047 µg/L, fitting for the intended purposes at the concentrations of interest. This method was applied during a monitoring activity in an Italian volcanic lake in Viterbo (Lazio Region, Italy), due to a severe algal proliferation in January 2018-March 2019 period and for the assessment of cyanobacteria proliferation risk and of cyanotoxin production in drinking water chain.
