Abstract
A method for analysis of okadaic acid (OA), dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2) using deproteination
cartridge filter was developed. This is a simple method because it does not require complicated operations such as conditioning
and washing of the column. The shellfish poisons in oyster were extracted with methanol and methanol/water (9:1), and were
hydrolyzed with 2.5 mol/L sodium hydroxide solution. The crude extracts were defatted by liquid- liquid partition using n-hexane,
and were passed through a deproteination cartridge filter. Measurement was performed by liquid chromatography tandem mass
spectrometry. As a result of the validation study using the matrix calibration curve method, the trueness, repeatability and withinlaboratory
reproducibility were 92-98, 1.0-3.0 and 2.0-4.0%, respectively, and met the target values of notification of Ministry of
Health, Labour and Welfare of Japan.
