title: Liquid chromatographic determination of microcystins in water samples following pre-column excimer fluorescence derivatization with 4-(1-pyrene)butanoic acid hydrazide.
abstract: A method to measure the concentrations of microcystins (MCs) in water samples has been developed by incorporating pre-column fluorescence derivatization and liquid chromatography (LC). A solid-phase extraction for pretreatment was used to extract the MCs in water samples. The MCs were derivatized with excimer-forming 4-(1-pyrene)butanoic acid hydrazide (PBH). The MCs could then be detected by fluorescence after separation with a pentafluorophenyl (PFP)-modified superficially porous (core shell) particle LC column. The derivatization reactions of MCs with PBH proceeded easily in the presence of 4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium (DMT-MM) as a condensation reagent, and the resulting derivatives could be easily separated on the PFP column. The derivatives were selectively detected at excimer fluorescence wavelengths (440-540 nm). The instrument detection limit and the instrument quantification limit of the MCs standards were 0.4-1.2 μg L(-1) and 1.4-3.9 μg L(-1), respectively. The method was validated at 0.1 and 1.0 μg L(-1) levels in tap and pond water samples, and the recovery of MCs was between 67 and 101% with a relative standard deviation of 11%. The proposed method can be used to quantify trace amounts of MCs in water samples.
authors.affiliation: Faculty of Pharmaceutical Sciences, Fukuoka University, Johnan, Fukuoka, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hayama
authors.forename: Kenji
authors.initials: K
authors.lastname: Katoh
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Aoki
authors.forename: Miki
authors.initials: M
authors.lastname: Itoyama
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Todoroki
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nohta
mesh_terms: D002623:Chemistry Techniques, Analytical; D002853:Chromatography, Liquid; D006834:Hydrazines / Q000737:chemistry*; D052998:Microcystins / Q000737:chemistry*; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry*; D014881:Water Supply
chemical_list: D006834:Hydrazines; D052998:Microcystins; D014867:Water; C033471:pyrenebutyrylhydrazine