微囊藻毒素的液-质谱联用和直接进样检测方法比较

发布时间：2019/11/4 15:42:02     浏览次数：1081

微囊藻毒素的液-质谱联用和直接进样检测方法比较
Comparison of Liquid Chromatography Tandem Mass Spectrometry and Direct Injection Methods for the Analysis of Microcystins
  
DOI：
中文关键词: 微囊藻毒素  液-质谱联用  直接进样  螺蛳

英文关键词: Microcystin  liquid chromatography tandem mass spectrometry  direct injection analysis  Melanioides

采用高效液相色谱-串联质谱（LC-MS/MS）技术和直接进样（DIA）技术对7种微囊藻毒素进行定性、定量分析，比较两种方法在精密度、灵敏度、经济性等方面的优缺点，并用于螺蛳中微囊藻毒素的检测。LC-MS/MS技术选用Waters XSelect HSS T3（2.1 mm × 150 mm，3.5 μm），用0.1%甲酸水溶液-0.1%甲酸乙腈溶液作流动相，在电喷雾离子源（ESI）正离子多反应离子检测模式（MRM）下扫描，线性范围为0.9965~0.9993，相对标准偏差3.6%~6.1%，检出限和定量限分别小于0.54 ng/mL和1.81 ng/mL，回收率介于73.9%~83.4%之间。DIA技术选用碎片m/z 135.2为特征母核，优化选定DP 60 eV和CE 55 eV，经母离子扫描（PreIS）得到各微囊藻毒素的离子峰较为纯净，均以[M+2H]2+为主。两种方法比较结果显示：LC-MS/MS各项参数均优于DIA，而DIA检测速度较快，仅需1 min即可完成7种微囊藻毒素的快速测定。应用两种方法对60个随机样品的检测表明，螺蛳中的微囊藻毒素阳性率达到63.3%，主要污染种类为MC-RR和LR。根据研究结果建议当待测样品数量较多时，首先采用DIA进行初次筛选，对于阳性样品利用LC-MS/MS进行二次检测，可有效减少检测时间、色谱柱损耗及溶剂消耗，提高结果的可靠性。本分析策略可用于快速分析水体及动植物中的微囊藻毒素残留，确定监测物种、采样站位和频率、警戒值和防控反应机制等，为相关部门完善和强化水产品监测和管理工作提供科学依据，从而保障食用安全和近岸养殖业的健康发展。

 Seven molecular species of microcystins were qualitatively and quantitatively analyzed by both high performance liquid chromatography-tandem mass spectrometry （LC-MS/MS） and direct injection analysis （DIA）. The advantages and disadvantages of these two methods in precision， sensitivity and economy were compared， which were further used for the detection of microcystins in Melanioides. For LC-MS/MS method， the Waters XSelect HSS T3 （2.1 mm × 150 mm， 3.5 μm） was used as separation column with mobile phase of acetonitrile（0.1% formic acid） and water （0.1% formic acid）. The MS was operated in electrospray ionization（ESI） and multiple reaction monitoring mode（MRM） with linear range of 0.9965~0.9993 and relative standard deviation of 3.6%~6.1%. The limit of detection and the limit of quantitation were less than 0.54 ng/mL and 1.81 ng/mL， respectively. The recovery ranged from 73.9% to 83.4%. For DIA method， the fragment m/z 135.2 was selected as the characteristic ion with DP 60 eV and CE 55 eV. After precursor ion scanning （PreIS）， the microcystin were mainly ionized as [M+2H]2+. The comparison results of these two methods showed that the performance of LC-MS/MS was better than that of DIA， while DIA was faster in detection speed， which only cost one min to complete the determination of seven molecular species of microcystins. Finally， a total of 60 samples was analyzed by the two methods. The results showed that the positive samples were 63.3%， and the main pollution species were Mc-RR and LR. The results suggested that when the number of samples to be tested was large， DIA should be used for initial screening. For the positive samples， LC-MS/MS should be used for the secondary testing， which could effectively reduce the detection time， column loss and solvent consumption， and improve the reliability of the results. This analysis strategy can be applied to fast analysis of microcystins in water， animal， and plant samples， determine the monitoring and sampling position and frequency， the alert value， and the prevention and control， etc. This study could provide scientific basis for related departments to improve and strengthen the monitoring and management of aquatic products. It also could ensure the food safety and the development of offshore aquaculture.