Gas-chromatographic determination of trace amounts of tetrodotoxin in water,drugs, and blood plasma

A method has been developed for the determination of tetrodotoxin in water, blood plasma, and drugs at a level of 0.05—1.0 µg/mL. The method is based on the hydrolytic decomposition of tetrodotoxin by a sodium hydroxide solution, extraction of 2-amino-6-hydroxymethyl-8-hydroxyquinazoline using liquid–liquid extraction, preparation of its derivative by reaction with N,O-bis(trimethylsilyl)trifluroacetamide, and the determination of the derivative by gas–liquid chromatography with a mass-spectrometric detector.