Determination of Five Lipophilic Marine Toxins in Shellfish by Liquid Chromatography with Tandem Mass Spectrometry

A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of five lipophilic marine toxins including Gymnodimine (GYM), Spirolide-1 (SPX1), Okadaic acid (OA) Pecenotoxin-2 (PTX2) and Azaspiracid-1 (AZA1) in shellfish was developed. After being extracted with methanol and water (80/20, V/V), the extract was cleaned by solid phase extraction of MAX column, then determined by a reversed phase HPLC gradient program coupled with tandem mass spectrometry in selected-reaction-monitoring mode. GYM, SPX1, OA, PTX2, AZA1 were analyzed in positive ion mode, while OA in negative ion mode. The calibration curves were linear well between LC peak area of the selected ion-pair and the concentration of five lipophilic marine toxins with the correlation coefficient over 0.99. The average recoveries from spiked scallop muscle at the concentration ranged from 78.6% to 94.4% with relative standard deviation from 6.8% to 14.9%. The limits of detection were 0.10, 0.21, 2.00, 0.32 and 0.04 mu g/kg for GYM, SPX1, OA, PTX2 and AZA1 respectively.