Development of a capillary zone electrophoretic method for the rapid separation and detection of hepatotoxic microcystins

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  • Paul C. H. Li
  • Shen Hu
  • Paul K. S. Lam


Original languageEnglish
Pages (from-to)250-254
Journal / PublicationMarine Pollution Bulletin
Issue number1-12
Publication statusPublished - Jan 1999


Analysis of trace amounts of various hepatotoxic microcystins in marine and freshwater samples is very important since these toxins, especially microcystin-LR, have been demonstrated to have tumour-promoting activity. In this study, instead of measuring the total amount of microcystins, we developed a capillary zone electrophoretic method for the separation and detection of individual toxin standards. No additives were used for enhancement of resolution. This technique is characterized by a high separation efficiency, short analysis time and small sample volume. In order to improve the detection sensitivity, a laser-induced fluorescence detector was used, and the labelling of microcystins was accomplished through a two-step procedure. First, the microcystin standards were converted into cysteine conjugates, followed by derivatization with Fluorescein 5-Isothiocyanate (FITC). After derivatization, the FITC-labelled microcystins were directly injected, separated and detected in 8 min. This method was shown to be a promising technique for sensitive and rapid analysis of individual microcystin toxins. Copyright (C) 1999 Elsevier Science Ltd.