Determination of microcystins in fish by solvent extraction and liquid chromatography.
A liquid chromatography electrospray mass spectrometry (LC/ESI/MS) method has been developed to identify and quantify microcystins in fish liver and intestine. Microcystins (MCs) were extracted from 500 mg sample with methanol-water (85:25, v/v) and the extracts concentrated to 250 microl. The parameters were optimized by a full factorial 2(3) design. Neither laborious pre-treatment nor clean up were necessary. MCs were separated using conventional C18 column and an acetonitrile-acidified water (pH 3) gradient. Negative samples (without MCs) were discriminated by liquid chromatography diode array detection (LC/DAD). The limits of detection (LOD) and the limits of quantification (LOQ) resulted equal for MC-RR, MC-YR, and MC-LR and were 0.1 and 0.5 microg g(-1), respectively. MCs recoveries at three levels in spiked samples (0.5-3.0 microg g(-1)) were > 92%, with relative standards deviations (RSDs) < 16% for liver samples and > 68% with RSDs < 18% for intestine samples. The proposed method was applied to determine MC-LR in exposed fish to evaluate the bioaccumulation risk. The results showed the transference of MC-LR from cyanobacterial cells to fish tissues.
Moreno
Isabel María
IM
Area de Toxicología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
Molina
Rafael
R
Jos
Angeles
A
Picó
Yolanda
Y
Cameán
Ana María
AM
D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification*; D005591:Chemical Fractionation / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D000458:Cyanobacteria / Q000737:chemistry; D007422:Intestines / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D008387:Marine Toxins / Q000302:isolation & purification*; D052998:Microcystins; D010456:Peptides, Cyclic / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D017210:Tilapia
D001427:Bacterial Toxins; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C078588:microcystin; C057862:cyanoginosin LR