A simplified liquid–liquid micro-extraction (LLME) GC/MS/MS method was developed for the determination of 18 polycyclic aromatic hydrocarbons (PAHs) in surface water. This method utilizes a pseudo multiple reaction monitoring (PMRM) mode, a technique in which the third quadrupole monitors the same m/z as for the first quadrupole precursor ion. The use of helium as the only collision gas improved the sensitivity by significantly reducing both PAH compound fragmentation and baseline noise. For PAH determination, the PMRM approach proved superior to the classical quadrupole MRM technique in terms of enhanced sensitivity. With observed improvements in sensitivity, micro-extraction using only 4 mL of a novel binary solvent became possible, with corresponding reduction in time consuming sample preparation procedures and toxic solvent usage. Quantifying and qualifying ions, in addition to retention times, were used to verify trace level PAHs. During method validation, the limit of quantitation (LOQ) in surface water was observed to be 10 ng L⁻¹ for the target PAHs. The recovery of individual PAHs was in the range of 80 to 114% from a water matrix, with a corresponding precision between 1.4 and 4.8% RSD. The robustness and accuracy of this method was demonstrated by its success in repeated proficiency test studies. The procedure has been successful during routine use in environmental sample testing and analysis of chemically enhanced water accommodated fraction (CEWAF) samples from toxicological LC50 (50% lethal concentration) bioassays, showing its applicability to situations in which both crude oil and oil spill dispersants are present.

中文翻译：

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使用简化的液-液微萃取和假MRM GC / MS / MS测定地表水中的多环芳烃†

开发了一种简化的液-液微萃取（LLME）GC / MS / MS方法，用于测定地表水中的18种多环芳烃（PAHs）。该方法利用了伪多反应监测（PMRM）模式，该技术中第三个四极杆监测相同的m / z至于第一个四极前体离子 使用氦气作为唯一的碰撞气体可通过显着减少PAH化合物碎片和基线噪音来提高灵敏度。对于PAH的测定，在提高灵敏度方面，PMRM方法被证明优于传统的四极MRM技术。随着灵敏度的提高，仅使用4 mL的新型二元溶剂进行微萃取成为可能，相应地减少了耗时的样品制备程序和有毒溶剂的使用。除保留时间外，还对离子进行了定量和定性，以验证痕量PAH。在方法验证期间，观察到地表水中的定量极限（LOQ）为10 ng L ^-1目标PAH。从水基质中回收的多环芳烃含量在80％至114％之间，相应的精密度在RSD的1.4％至4.8％之间。该方法的鲁棒性和准确性已通过其在重复能力验证研究中的成功证明。该程序在环境样品测试和毒理学LC50（50％致死浓度）生物测定法中化学增强的水分保留分数（CEWAF）样品的常规使用中已成功完成，表明该方法适用于原油和溢油分散剂均处于危险状态的情况。展示。