title: Potential of a simple solid-phase extraction method coupled to analytical and bioanalytical methods for an improved determination of microcystins in algal samples.
abstract: Artemia assays and protein phosphatase assays are commonly used for the screening of microcystins (MCs) in algal samples instead of the standard mouse toxicity assay. However, it has been shown that their results are often biased because of the matrix effects. To eliminate the possible interferences in the algal matrices, a new solid-phase extraction (SPE) method using silica gel as a sorbent was developed and evaluated. Results show that this SPE method could not only reduce the toxicity of the Microcystis samples towards brine shrimp by 50-80% but also eliminate 90-100% of the endogenous phosphatase activity from Spirulina and Chlorella samples, thus improving the determination of microcystins in algal samples using either of the two bioanalytical methods. The application of this SPE method as an off-line cleanup for high-performance liquid chromatography (HPLC) with UV detection is also described in this study. After SPE, the HPLC chromatograms of Microcystis samples have clear baselines that have no interferences with the analyte peaks.
authors.affiliation: Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan, ROC. cohens.tw@yahoo.com.tw
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Chen
authors.forename: Tzong-Huei
authors.initials: TH
authors.lastname: Lee
authors.forename: Shyh-Jye
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jian-Zhi
authors.initials: JZ
authors.lastname: Lin
authors.forename: Rang
authors.initials: R
authors.lastname: Huang
authors.forename: Hong-Nong
authors.initials: HN
authors.lastname: Chou
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019587:Dietary Supplements; D056890:Eukaryota / Q000737:chemistry*; D051379:Mice; D052998:Microcystins / Q000032:analysis*; D012015:Reference Standards; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D052998:Microcystins