Marine Institute, Renville, Oranmore, Co. Galway, Ireland.
J Chromatogr A. 2010 Nov 5;1217(45):7123-30. doi: 10.1016/j.chroma.2010.09.020. Epub 2010 Sep 16.
Considerable efforts are being made worldwide to replace in vivo assays with instrumental methods of analysis for the monitoring of marine biotoxins in shellfish. Analysis of these compounds by the preferred technique of liquid chromatography tandem mass spectrometry (LC-MS/MS) is challenged by matrix effects associated with the shellfish tissues. In methods validation, assessment of matrix interferences is imperative to ensure the validity and accuracy of results being produced. Matrix interferences for the analysis of okadaic acid (OA) and azaspiracid 1 (AZA1) were assessed using acidic methods on electrospray triple stage quadrupole (TSQ) and hybrid quadrupole time of flight (QToF) instruments by the use of matrix matched standards for different tissue types. Using an acidic method no matrix interference and suppression was observed on the TSQ for OA and AZA1 respectively, whilst the opposite was observed on the QToF; matrix enhancement for OA and no matrix interference for AZA1. The suppression of AZAs on the TSQ was found to be due to interfering compounds being carried over from previous injections. The degree of suppression is very much dependant on the tissue type ranging from 15 to 70%. Several strategies were evaluated to eliminate these interferences, including the partitioning of the extract with hexane, optimisation of the chromatographic method and the use of on-line SPE. Hexane clean up did not have any impact on matrix effects. The use of an alkaline method and a modified acidic method eliminated matrix suppression for AZA1 on the TSQ instrument while an on-line SPE method proved to be effective for matrix enhancement of OA on the QToF.
全世界正在做出相当大的努力，用仪器分析方法代替活体检测方法，以监测贝类中的海洋生物毒素。采用液相色谱串联质谱（LC-MS/MS）的首选技术分析这些化合物时，受到贝类组织中基质效应的挑战。在方法验证中，评估基质干扰对于确保产生的结果的有效性和准确性是至关重要的。通过使用不同组织类型的基质匹配标准品，对电喷雾三级四极杆（TSQ）和混合四极杆飞行时间（QToF）仪器上的酸性方法进行分析，评估了 okadaic 酸（OA）和azaspiracid 1（AZA1）的基质干扰。采用酸性方法时，OA 和 AZA1 在 TSQ 上均未观察到基质干扰和抑制，而在 QToF 上则观察到相反的情况；OA 存在基质增强，AZA1 则不存在基质干扰。在 TSQ 上观察到 AZAs 的抑制是由于先前注射时携带的干扰化合物所致。抑制的程度在很大程度上取决于组织类型，范围从 15%到 70%不等。评估了几种策略来消除这些干扰，包括用正己烷对提取物进行分配、优化色谱方法和使用在线 SPE。正己烷净化对基质效应没有任何影响。采用碱性方法和改良的酸性方法消除了 AZA1 在 TSQ 仪器上的基质抑制，而在线 SPE 方法被证明对 QToF 上 OA 的基质增强有效。
