Applied Environmental Research Laboratories, Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia V9R 5S5, Canada; Department of Chemistry - BMC, Uppsala University, Box 576, 751230 Uppsala, Sweden.
Applied Environmental Research Laboratories, Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, British Columbia V9R 5S5, Canada; Department of Chemistry, University of Victoria, PO Box 1700, Stn CSC, Victoria, British Columbia V8W 2Y2, Canada.
Sci Total Environ. 2020 May 10;716:137063. doi: 10.1016/j.scitotenv.2020.137063. Epub 2020 Feb 1.
The application of direct mass spectrometry techniques to the analysis of complex samples has a number of advantages including reduced sample handling, higher sample throughput, in situ process monitoring, and the potential for adaptation to on-site analysis. We report the application of a semi-permeable capillary hollow fibre membrane probe (immersed directly into an aqueous sample) coupled to a triple quadrupole mass spectrometer by a continuously flowing methanol acceptor phase for the rapid analysis of naphthenic acids with unit mass resolution. The intensity of the naphthenic acid-associated peaks in the mass spectrum are normalized to an internal standard in the acceptor phase for quantitation and the relative abundance of the peaks in the mass spectrum are employed to monitor compositional changes in the naphthenic acid mixture using principle component analysis. We demonstrate the direct analysis of a synthetic oil sands process-affected water for classical naphthenic acids (CHO) as they are attenuated through constructed wetlands containing sedge (Carex aquatilis), cattail (Typha latifolia), or bulrush (Schoenoplectus acutus). Quantitative results for on-line membrane sampling compare favourably to those obtained by solid-phase extraction high-resolution mass spectrometry. Additionally, chemometric analysis of the mass spectra indicates a clear discrimination between naphthenic acid-influenced and natural background waters. Furthermore, the compositional changes within complex naphthenic acid mixtures track closely with the degree of attenuation. Overall, the technique is successful in following changes in both the concentration and composition of naphthenic acids from synthetic oil sands process-affected waters, with the potential for high throughput screening and environmental forensics.
直接质谱技术在分析复杂样品方面具有许多优势，包括减少样品处理、提高样品通量、原位过程监测以及适应现场分析的潜力。我们报告了一种半渗透毛细管空心纤维膜探头（直接浸入水溶液中）的应用，该探头通过连续流动的甲醇接受相与三重四极杆质谱仪耦合，用于快速分析具有单位质量分辨率的环烷酸。质谱中与环烷酸相关的峰的强度通过接受相中的内标进行归一化以进行定量，并且通过主成分分析，采用质谱中峰的相对丰度来监测环烷酸混合物的组成变化。我们证明了通过含有莎草（Carex aquatilis）、香蒲（Typha latifolia）或菰（Schoenoplectus acutus）的人工湿地直接分析合成油砂加工影响水的经典环烷酸（CHO）。在线膜采样的定量结果与固相萃取高分辨率质谱法获得的结果相当。此外，对质谱的化学计量分析表明，环烷酸影响的水和天然背景水之间存在明显的区分。此外，复杂环烷酸混合物的组成变化与衰减程度密切相关。总体而言，该技术成功地跟踪了来自合成油砂加工影响水的环烷酸浓度和组成的变化，具有高通量筛选和环境取证的潜力。
