Department of Analytical Chemistry, Physical Chemistry and Inorganic Chemistry, National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM), Institute of Chemistry, São Paulo State University (UNESP), Araraquara, São Paulo 14800-060, Brazil.
Department of Analytical Chemistry, Physical Chemistry and Inorganic Chemistry, Institute of Chemistry, São Paulo State University (UNESP), Araraquara, SP 14800-060, Brazil.
J Chromatogr A. 2024 Aug 16;1730:465038. doi: 10.1016/j.chroma.2024.465038. Epub 2024 Jun 8.
This study addresses the analysis of emerging contaminants, often using chromatographic techniques coupled to mass spectrometry. However, sample preparation is often required prior to instrumental analysis, and dispersive liquid-liquid microextraction (DLLME) is a viable strategy in this context. DLLME stands out for its ability to reduce sample and solvent volumes. Notably, dispersive liquid-liquid microextraction using magnetic ionic liquids (MILs) has gained relevance due to the incorporation of paramagnetic components in the chemical structure, thereby eliminating the centrifugation step. A pyrolizer was selected in this work to introduce sample onto the GC column, since the MIL is extremely viscous and incompatible with direct introduction through an autosampler. This study is the first to report the use of a DLLME/MIL technique for sample introduction through a pyrolizer in gas chromatography coupled to mass spectrometry (GC-MS). This approach enables the MIL to be compatible with gas chromatography systems, resulting in optimized analytical and instrument performance. The analysis of polybrominated diphenyl ether flame retardants (PBDEs) was focused on the PBDE congeners 28, 47, 99, 100, and 153 in sewage sludge samples. The [P][MnCl] MIL was thoroughly characterized using UV-Vis, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy, as well as thermal analysis. In the chromatographic method, a pyrolyzer was used in the sample introduction step (Py-GC-MS), and critical injection settings were optimized using multivariate approaches. Optimized conditions were achieved with a temperature of 220 °C, a pyrolysis time of 0.60 min, and an injection volume of 9.00 μL. DLLME optimization was performed through central compound planning (CCD), and optimized training conditions were achieved with 10.0 mg of MIL, 3.00 μL of acetonitrile (ACN) as dispersive solvent, extraction time of 60 s, and volume of a sample of 8.50 mL. Precision was observed to range from 0.11 % to 12.5 %, with limits of detection (LOD) of 44.4 μg L for PBDE 28, 16.9 μg L for PBDE 47 and PBDE 99, 33.0 μg L for PBDE 100 and 375 μg L for PBDE 153. PBDE 28 was identified and analyzed in the sludge sample at a concentration of 800 μg L. The use of MIL in dispersive liquid-liquid microextraction combined with pyrolysis gas chromatography-mass spectrometry enables identification and quantification of PBDEs in sewage sludge samples at concentrations down to the µg L level.
本研究旨在分析新兴污染物，通常使用色谱技术与质谱联用。然而，在仪器分析之前，通常需要进行样品前处理，而分散液-液微萃取（DLLME）是一种可行的策略。DLLME 的突出特点是能够减少样品和溶剂的用量。值得注意的是，由于在化学结构中引入了顺磁成分，因此使用磁性离子液体（MILs）的分散液-液微萃取消除了离心步骤。在这项工作中，选择了热解器将样品引入 GC 柱，因为 MIL 非常粘稠，与自动进样器直接进样不兼容。这是首次报道使用 DLLME/MIL 技术通过热解器将样品引入气相色谱-质谱联用仪（GC-MS）中。这种方法使 MIL 能够与气相色谱系统兼容，从而优化了分析和仪器性能。本研究集中分析了污水污泥样品中多溴二苯醚阻燃剂（PBDEs）的 28、47、99、100 和 153 种同系物。使用紫外-可见分光光度法、傅里叶变换红外光谱（FTIR）和拉曼光谱以及热分析对 [P][MnCl] MIL 进行了全面表征。在色谱方法中，在样品引入步骤中使用了热解器（Py-GC-MS），并使用多元方法优化了关键进样设置。在 220°C 的温度下，0.60 分钟的热解时间和 9.00 μL 的进样量实现了最佳条件。通过中心复合规划（CCD）对 DLLME 进行了优化，优化后的训练条件为 10.0 mg MIL、3.00 μL 乙腈（ACN）作为分散溶剂、萃取时间 60 s 和 8.50 mL 样品体积。观察到精度范围在 0.11%至 12.5%之间，检出限（LOD）为 PBDE 28 为 44.4 μg L，PBDE 47 和 PBDE 99 为 16.9 μg L，PBDE 100 为 33.0 μg L，PBDE 153 为 375 μg L。在污泥样品中鉴定和分析了 PBDE 28，浓度为 800 μg L。MIL 在分散液-液微萃取中的应用与热解气相色谱-质谱联用，能够在 µg L 水平下鉴定和定量分析污水污泥样品中的 PBDEs。
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