超高效液相色谱-串联质谱法测定海水悬浮颗粒物中的8种典型脂溶性藻毒素

海水悬浮颗粒物对海洋环境中污染物的迁移转化有着重要的影响,在海水悬浮颗粒物上富集的脂溶性藻毒素会严重的毒害海洋滤食性生物。本研究建立了海水悬浮颗粒物中8种典型脂溶性藻毒素同步测定的超高效液相色谱-串联质谱( UPLC-MS/MS)分析方法。海水悬浮颗粒物样品经甲醇超声辅助提取后,以5 mmol/L 乙酸铵水溶液和乙腈为流动相,经1.7微米C18色谱柱分离,采用电喷雾串联质谱( ESI-MS/MS)多反应监测( MRM )模式检测,外标法定量。结果表明,在最佳实验条件下,8种目标物在5 min内分离良好,加标回收率在83.8%~110.4%之间,方法具有良好的精密度(相对标准偏差( RSD)≤14.1%)和灵敏度(检出限介于2.9~103 pg/g之间),在线性范围内,相关系数(R2)均大于0.996,能满足海水悬浮颗粒物中8种典型脂溶性藻毒素同步检测的要求。采用本方法初步分析了青岛沿岸海域海水悬浮颗粒物中的脂溶性藻毒素,其中PTX2被检出,含量最高可达790 pg/g(干重)。

Determination of Eight Typical Lipophilic Algae Toxins in Particles Suspended in Seawater by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

The particles suspended in seawater have great influence on pollutant migration and transformation in marine environment, while the lipophilic algae toxins enriched by the particles suspended in seawater will lead more serious toxicity to marine filter feeders. In this study, a new method was developed for the simultaneous determination of eight lipophilic algae toxins in suspended particles by ultra performance liquid chromatography-tandem mass spectrometry ( UPLC-MS/MS ) . After extracted with methanol by ultrasonic-assisted extraction, the sample was separated on an Acquity UPLC BEH C18 column (50 mm×2. 1 mm, 1. 7 μm) using gradient elution of acetonitrile and water containing 5 mmol/L ammonium acetate as eluent modifiers. The qualitative and quantitative analyses were carried out by electrospray ionization ( ESI) tandem mass spectrometry in multiple reaction monitoring ( MRM) mode. Under the optimal conditions, satisfactory precision (relative standard deviations (RSD≤14. 1%), recoveries (83. 8%-110. 4%) and detection limits (2. 9-103 pg/g) of the method were achieved. Good linearity (R2≥0. 99) was also obtained for all studied analytes. Then, the method was applied to determine the amounts of the eight lipophilic marine toxins in authentic suspended particle samples collected from Qingdao near-shore area. Pectenotoxin 2 ( PTX2 ) was detected in the samples from Shilaoren beach and No. 3 bathing beach with concentration ranges of 717 and 790 pg/g, respectively.