National University of Singapore Environmental Research Institute, National University of Singapore, T-Lab Building #02-01, 5A Engineering Drive 1, Singapore 117411, Singapore.
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
J Chromatogr A. 2021 Jan 25;1637:461828. doi: 10.1016/j.chroma.2020.461828. Epub 2020 Dec 19.
A novel double-microextraction approach, combining dispersive liquid-liquid microextraction (DLLME) and vortex-assisted micro-solid-phase extraction (VA-µ-SPE) was developed. The procedure was applied to extract endocrine disrupting chemicals (EDCs) consisting of three phthalate esters (PEs) and bisphenol A (BPA) associated with PM (airborne particulate matter with aerodynamic diameter ≤ 2.5 µm). Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used for determination of the analytes. These analytes were first ultrasonically desorbed from PM in a 10% acetone aqueous solution. DLLME was used to first preconcentrate the analytes; the sample solution, still in the same vial, was then subjected to VA-µ-SPE. The synergistic effects provided by the combination of the microextraction techniques provided advantages such as high enrichment factors and good cleanup performance. Various extraction parameters such as type and volume of extractant solvent (for DLLME), and type of sorbent, extraction time, desorption solvent, volume of desorption solvent and desorption time (for µ-SPE) were evaluated. Multi-walled carbon nanotubes were found to be the most suitable sorbent. This procedure achieved good precision with intra- and inter-day relative standard deviations of between 1.93 and 9.95%. Good linearity ranges (0.3-100 ng/mL and 0.5-100 ng/mL, depending on analytes), and limits of detection (LODs) of between 0.07 and 0.15 ng/mL were obtained. The method was used to determine the levels of PEs and BPA in ambient air, with concentrations ranging between below the limits of quantification and 0.48 ng/m. DLLME-VA-µ-SPE-GC-MS/MS was demonstrated to be suitable for the determination of these EDCs present in PM.
开发了一种新颖的双重微萃取方法，结合分散液液微萃取（DLLME）和涡旋辅助微固相萃取（VA-µ-SPE）。该程序用于提取与 PM（空气动力学直径≤2.5 µm 的空气悬浮颗粒物）相关的内分泌干扰化学物质（EDC），包括三种邻苯二甲酸酯（PE）和双酚 A（BPA）。气相色谱-串联质谱（GC-MS/MS）用于测定分析物。这些分析物首先在 10%丙酮水溶液中从 PM 超声解吸。DLLME 用于首次预浓缩分析物；然后将样品溶液仍在同一小瓶中进行 VA-µ-SPE。微萃取技术的组合提供了协同作用，具有高富集因子和良好的净化性能等优点。评估了各种萃取参数，例如萃取溶剂（DLLME 用）的类型和体积，以及吸附剂的类型、萃取时间、解吸溶剂、解吸溶剂体积和解吸时间（µ-SPE 用）。发现多壁碳纳米管是最适合的吸附剂。该程序实现了良好的精密度，日内和日间相对标准偏差在 1.93%至 9.95%之间。获得了良好的线性范围（取决于分析物，0.3-100 ng/mL 和 0.5-100 ng/mL）和检测限（LODs）在 0.07 和 0.15 ng/mL 之间。该方法用于测定环境空气中 PE 和 BPA 的水平，浓度范围在定量下限和 0.48 ng/m 之间。DLLME-VA-µ-SPE-GC-MS/MS 被证明适用于测定 PM 中存在的这些 EDC。
