title: Quantitative determination of paralytic shellfish toxins in cultured toxic algae by LC-MS/MS.
abstract: We developed a sample preparation and LC-MS/MS method for the determination of saxitoxins in toxic algae. Paralytic shellfish toxins (PSTs) were successfully separated by gradient elution on an amide column with the hydrophilic interaction mode and quantified with multiple reaction monitoring (MRM) detection in the positive ion mode. This method showed good performance in the summed LODs and LOQs for all 12 toxins, 25 and 84 nM, respectively. Next, extracts of cultured strains of a toxic dinoflagellate Alexandrium tamarense and a freshwater cyanobacteria Anabaena circinalis were treated in a short column of basic alumina and the toxic fractions were analysed by our LC-MS/MS method and by HPLC with fluorescence detection. Comparison of the results obtained by the two methods demonstrated that approximately equivalent results were obtained for both the dinoflagellate and the cyanobacteria. In addition, the retention time of the toxins showed acceptable shifts. Therefore, the clean-up of the toxic algal extracts by using the basic alumina column controlled unwanted chromatographic behaviour and variable ionisation efficiency during MS detection. LC-MS/MS for saxitoxins has great potential as a rapid analytical method for determining all primary saxitoxins in cultured algae.
authors.affiliation: Research Centre for Biochemistry and Food Technology, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Yokohama 236-8648, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Watanabe
authors.forename: Ryoji
authors.initials: R
authors.lastname: Matsushima
authors.forename: Tomoko
authors.initials: T
authors.lastname: Harada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oikawa
authors.forename: Masakazu
authors.initials: M
authors.lastname: Murata
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D017033:Anabaena / Q000737:chemistry; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D004141:Dinoflagellida / Q000737:chemistry; D008387:Marine Toxins / Q000032:analysis*; D015394:Molecular Structure; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D008387:Marine Toxins