Determination of ciguatoxin in fish by liquid chromatography tandem mass spectrometry and comparison with mouse bioassay

Abstract

A visibly unidentifiable colourless, odourless, heat stable, lipid soluble polyether marine biotoxin known as Ciguatoxin (CTX) responsible for human illness has been identified from certain fish collected from Cochin, Trivandrum and Mangalore. Our study showed that among the 14 species collected, Lutjanus bohar has been identified for ciguatoxicity. Detection of the toxin was done using mouse bioassay which showed symptoms related to suspected CTX toxicity. Significantly, a higher level of 2.17 mouse unit Ciguatoxin was estimated which is equivalent to 10.84 ng of CTX toxicity and 13% of weight loss. Solid phase extraction was employed for the separation and purification of the toxin from the fish extract, which was confirmed and quantified by gradient reverse phase liquid chromatography tandem mass spectrometry. The Extracted Ion Chromatogram of CTX fish extract of Lutjanus bohar showed m per z 1117.303 Da precursor/product confirmatory ion transitions.