QuEChERS净化技术结合超高效液相色谱-串联质谱法筛查食用贝类中的3种原多甲藻酸贝类毒素

采用超高效液相色谱-串联质谱(UHPLC-MS/MS)技术,建立了贻贝、牡蛎、蚌类、扇贝等食用贝类及其制品中3种天然形式的原多甲藻酸(azaspiracid-1, azaspiracid-2, azaspiracid-3)贝类毒素的检测方法。样品采用乙腈-水(85:15, v/v)混合液均质提取,应用QuEChERS技术净化,以0.2 μm微孔滤膜过滤,在乙腈-水(含5 mmol/L醋酸铵和0.1%甲酸)体系下进行梯度洗脱,并在ZORBAX Eclipse Plus C₁₈柱(100 mm×2.1 mm, 1.8 μm)上实现3种贝类毒素的基线分离。该方法采用多反应监测(MRM)模式扫描,采用标准曲线外标法定量。3种原多甲藻酸在1~100 μg/kg范围内线性关系良好,相关系数(r²)均大于0.995; 3种贝类毒素的定量限(S/N=10)均为1.0 μg/kg;在10、20和50 μg/kg 3个加标水平的添加回收率在71%~108%之间,日内和日间测定的相对标准偏差≤10%(n=6)。应用该方法对国内外多个地区的贝类产品进行了筛查测定,发现部分样品的测定结果为阳性。该方法灵敏度高,重复性好,操作简便、快捷,适用于食用贝类及其制品中3种原多甲藻酸贝类毒素的分析测定。

Determination of three azaspiracids in edible shellfishes by QuEChERS method combined with ultra high performance liquid chromatography-tandem mass spectrometry

An ultra high performance liquid chromatography-tandem mass spectrometric method (UHPLC-MS/MS) was developed for the simultaneous determination of three natural forms of azaspiracids (AZA-1, AZA-2 and AZA-3) in edible shellfishes such as mussels, oysters, clams and scallops. The samples were homogeneously extracted with acetonitrile-water (85:15, v/v). The resultant supernatants were purified with QuEChERS method and filtrated by 0.2 μm microporous filters. The separation was performed on an Agilent ZORBAX Eclipse Plus C₁₈ column (100 mm×2.1 mm, 1.8 μm) with the gradient elution using acetonitrile/water (containing 5 mmol/L ammonium acetate and 0.1% formic acid) as mobile phases. The three azaspiracids were detected using positive electrospray ionization (ESI+) followed with multiple reaction monitoring (MRM), and quantified by external standard calibration method. The calibration curves showed good linearity in the range of 1-100 μg/kg with the correlation coefficients (r²) greater than 0.995. The limits of quantification (LOQ, S/N=10) were 1.0 μg/kg for all the three AZAs. The average recoveries of azaspiracids spiked in the matrix at the levels of 10, 20 and 50 μg/kg ranged from 71% to 108%. The relative standard deviations (RSDs) of inter-day and intra-day determinations were less than 10%(n=6). The samples from several areas within and outside of China were screened, and some of the samples showed positive for azaspiracids. The developed method is easy to operate, very reproducible, sensitive, and efficient. It can be applied to the determination of the three forms of AZAs in the edible shellfishes as well shellfish products.