title: Optimal strategies for determination of free/extractable and total microcystins in lake sediment.
abstract: The optimization of analytical procedures for the quantification of free and total microcystins (MCs) in natural sediments was systematically examined based on solvent extraction and Lemieux oxidation. In this optimized analytical procedure, a sequential solvent extraction using 50% (v/v) methanol and EDTA-sodium pyrophosphate was selected as the optimal extraction solvent for free MCs analysis, after which the purified extracts and sediment residuals were applied to the optimized Lemieux oxidation for determination of total MCs in lake sediments. The optimized procedures were shown to be efficient and reliable for the routine analysis of both free and total MCs in lake sediment samples, as indicated by the minimal adverse impact of sediment organic matter on the recovery of free MCs and yield of MMPB (2-methyl-3-methoxy-4-phenylbutyric acid). Finally, the developed procedures were applied to field sediment samples collected from Lake Dianchi during a bloom season and seven of thirty samples showed positive results.
authors: Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China.
authors: Xingqiang
authors: X
authors: Wu
authors: Chunbo
authors: C
authors: Wang
authors: Bangding
authors: B
authors: Xiao
authors: Yang
authors: Y
authors: Wang
authors: Na
authors: N
authors: Zheng
authors: Jingshuang
authors: J
authors: Liu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D011756:Diphosphates / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes; D059625:Liquid-Liquid Extraction; D000432:Methanol / Q000737:chemistry; D052998:Microcystins / Q000032:analysis* / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010654:Phenylbutyrates / Q000032:analysis / Q000302:isolation & purification; D012989:Soil Pollutants / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D011756:Diphosphates; D052998:Microcystins; D010654:Phenylbutyrates; D012989:Soil Pollutants; C078588:microcystin; C075773:4-phenylbutyric acid; D004492:Edetic Acid; C003319:sodium pyrophosphate; D000432:Methanol