液相色谱-高分辨质谱测定贝类中软骨藻酸

Determination of domoic acid in shellfish by liquid chromatography-orbitrap mass spectrometry

软骨藻酸(DA)是一种由拟菱形藻属硅藻产生的神经毒素,可累积在贝类体内,食用受软骨藻酸污染的贝类产品可引起记忆丧失、眩晕、昏迷甚至死亡等症状。研究建立了贝类产品中软骨藻酸的液相色谱-高分辨质谱检测方法。以牡蛎和文蛤为研究对象,样品经甲醇提取、采用QuEChERS净化,经Hypersil GOLD C18色谱柱分离,乙腈和2 mmol/L甲酸铵溶液(含0.2%甲酸)为流动相梯度洗脱,正离子全扫描+数据依赖二级扫描,提取一级谱图中准分子离子精确质量数定量,二级质谱图中特征离子精确质量数定性。结果表明,软骨藻酸在6 min内出峰,定量限0.01 mg/kg,在25~500μg/L线性良好,R2=0.999 8,回收率为90.5%~106.3%,相对标准偏差(RSD)小于6.0%(n=6)。该方法简单、快速、灵敏度高,能满足贝类中软骨藻酸的测定。

Domoic acid(DA)is a kind of neurotoxin produced by Pseudo-nitzschia diatom that can accumulate in shellfish. Consuming shellfish products contaminated by domoic acid can cause memory loss,dizziness,coma and even death. In this paper,a method was established for the simultaneous determination of domoic acid(DA) in shellfish by liquid chromatography-orbitrap mass spectrometry. Oyster and clam samples were extracted with methanol and purified with QuEChERS technology. The analytes were isolated by Hypersil GOLD C18 column and gradient eluted with acetonitrile-2 mmol/L ammonium formate solution(0.2% formic acid). DA were determined by orbitrap mass spectrometry through positive ion scanning,full scan mode and data dependent scan mode. The experimental results indicated that the retention time of DA was all within 6 min. The limits of quantification(LOQ)was 0.01 mg/kg. The calibration curves showed good linearity within the concentration range of 25~500 μg/L,R2=0.999 8. The average recoveries was between 90.5%~106.3% and the relative standard deviations(RSD)were less than 6.0%(n=6). This method was easy,rapid and sensitive,and could be applied in the determination of domoic acid in shellfish.