Determination of Azaspiracids Shellfish Poison in Bivalve Aquatic Product by Liquid Chromatography Tandem Mass Spectrometry

A method was established for the simultaneous determination of three main kinds of azaspiracids (AZAs) shellfish poison, such as azaspiracid 1 (AZA1), azaspiracid 2 (AZA2), azaspiracid 3 (AZA3) in bivalve aquatic product by liquid chromatography tandem mass spectrometry. The matrix representative shellfish including scallop, oyster and clam were extracted with 80% methanol-water solution, defatted by hexane, reextracted by chloroform subsequently, and then enriched by rotary evaporation before purified by solid phase extraction on a MAX solid phase extraction cartridge which contains a kind of mixed-mode sorbent with reversed-phase and anion-exchange functionalities. The analytes were isolated by reversed phase high performance liquid chromatography on a Luna C18 column (150 mm x 2. 0 mm, 5 mu m) and gradient eluted with acetonitrile-0. 1% formic acid at a flow rate of 1. 0 mL/min. AZAs were determined with the multiple reaction monitoring (MRM) mode by tandem mass spectrometry with electrospray detector through positive ion scanning. Quantitative analysis method was external standard method. The experimental results indicated that the retention time of AZAs was all within 4 min and the limit of quantification (LOQ) of them were all 1. 5 mu g/kg respectively, the calibration curves were linear in the range from 0. 3 mu g/L to 30 mu g/L, the average recoveries at spiked concentration of 1. 5, 60 and 120 mu g/kg were more than 80% and the relative standard deviations (RSDs) were less than 12% (n = 6).