贝类中大田软海绵酸的液相色谱-串联质谱优化测定法

Improvement of determination method of okadaic acid in shellfish by liquid chromatography-tandem mass spectrometry

目的建立测定贝类组织中腹泻性贝类毒素大田软海绵酸(okadaic acid,OA)的优化高效液相色谱-串联质谱方法。方法样品经0.125 mol/L盐酸性水溶液提取,乙酸乙酯萃取,HLB固相萃取小柱净化,采用液相色谱-串联质谱进行检测。结果以80%甲醇-水为流动相等度洗脱,流速为0.3 m L/min,柱温为35℃,选择正离子扫描和多反应监测(MRM)模式进行分析,OA在2~200μg/L范围内线性关系良好。采用本研究改进的前处理方法,4个添加水平下的回收率为90.5%~99.6%,高于采用行业标准SN/T2269-2009前处理方法的回收率(81.3%~87.5%),相对标准偏差小于10%,方法定量限(以S/N≥10计)为1.0μg/kg。成功应用本方法检测了湛江市市售的7种贝类样品,未检出OA。结论该优化方法灵敏度高,操作较简便,适合于多种贝类样品中OA的检测。

Objective High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been established for okadaic acid (OA) determination in shellfish products. Methods Shellfish sample was extracted by water solution containing 0.125 mol/L HCl. Shellfish extract solution was extracted with ethyl acetate and then cleaned-up by solid phase extraction (SPE) on an Oasis HLB cartridge and detected by HPLC-MS/MS. Results The detection was performed using 80%methanol-water (80:20, v/v) as a mobile phase with a flow rate at 0.3 mL/min, and a column temperature at 35 ℃. Positive ion mode and multiple reaction monitoring (MRM) mode were used in analysis. The calibration curve was linear in the range of 2~200μg/L. By adopting the improved pre-treatment method in present study, the recoveries of OA added at 4 concentration levels were 90.5%~99.6%, higher than the recoveries (81.3%~87.5%) of SN/T2269-2009 pre-treatment method. The quantification limit (LOD) (S/N≥10) of the method was 1.0μg/kg. By this method, there were no OA checked out from 7 kinds of shellfish samples from various markets in Zhanjiang city. Conclusion The developed method was highly sensitive and simple, and was suitable for determination of OA in many kinds of shellfish products.