Headspace Solid-Phase Microextraction Coupled to Miniaturized Microplasma Optical Emission Spectrometry for Detection of Mercury and Lead.
Headspace Solid-Phase Microextraction Coupled to Miniaturized Microplasma Optical Emission Spectrometry for Detection of Mercury and Lead.
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DOI：
10.1021/acs.analchem.7b04759
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发表时间：
2018-02
影响因子：
7.4
通讯作者：
C. Zheng;Li-gang Hu;X. Hou;B. He;G. Jiang
中科院分区：
文献类型：
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作者：
C. Zheng;Li-gang Hu;X. Hou;B. He;G. Jiang
尽管在过去的几年里，微等离子体原子光谱法的兴趣越来越大，但由于其灵敏度低，其在真实的样品现场分析中的应用仍然受到限制。采用PDMS/DVB光纤顶空固相微萃取（HS-SPME）进样方法，提高了小型（6.0cm长× 5.0cm宽× 2.8cm高）低功率（<10 W）微等离子体点放电发射光谱仪（PD-OES）的灵敏度。由于HS-SPME具有将样品基质中的分析物的采样、分离和预浓缩结合在一个步骤中的优点，HS-SPME不仅简化了样品前处理和实验装置，而且消除了基质和水蒸气的干扰，同时显着提高了分析性能。与光化学蒸气发生PD-OES相比，Hg和Pb的检测限提高了至少100倍，为真实的样品中这些和其他痕量元素的现场分析提供了巨大的潜力。在最佳条件下，汞和铅的检出限分别为0.001和0.003 μg L-1，相对标准偏差（RSD）分别优于2.1%和4.5%（1 μg L-1）。HS-SPME-PD-OES系统的准确性通过分析三种有证标准物质进行了验证，包括DORM-4（汞，412 ± 36 μg kg-1;铅，404 ± 62 μg kg-1），TORT-3（Hg，292 ± 22 μg kg-1; Pb，225 ± 18 μg kg-1）和SRM 1568 b（Hg，5.53 ± 0.58 μg kg-1），提供的分析结果在95%置信水平下与认证值非常一致。该方法也成功地用于分析几个真实的大米和水样品，结果令人满意（90-130%的加标回收率）。
Despite increased interest in microplasma atomic spectrometry over the past several years, its applications to field analysis of real samples still remain limited due to its low sensitivity. In this work, headspace solid-phase microextraction (HS-SPME) using PDMS/DVB fiber was used as a sample introduction method to improve the sensitivity of a miniature (6.0 cm length × 5.0 cm width × 2.8 cm height) low power (<10 W) microplasma point discharge optical emission spectrometer (PD-OES) for the determination of Hg and Pb after their derivatization with sodium tetraethylborate (NaBEt4). Owing to its advantages of combining sampling, separation, and preconcentration of analytes from sample matrices into a single step, HS-SPME not only simplifies sample pretreatment and the experimental setup but also eliminates interferences from matrices and water vapor while significantly improving analytical performance. In comparison to photochemical vapor generation PD-OES, limits of detection for Hg and Pb were enhanced by at least 100-fold, providing great potential for field analysis of these and other trace elements in real samples. Under optimal conditions, the limits of detection for Hg and Pb were 0.001 and 0.003 μg L-1, respectively, with relative standard deviations (RSDs) better than 2.1% and 4.5% at a concentration of 1 μg L-1. The accuracy of the HS-SPME-PD-OES system was validated by analysis of three Certified Reference Materials, including DORM-4 (Hg, 412 ± 36 μg kg-1; Pb, 404 ± 62 μg kg-1), TORT-3 (Hg, 292 ± 22 μg kg-1; Pb, 225 ± 18 μg kg-1) and SRM1568b (Hg, 5.53 ± 0.58 μg kg-1), providing analytical results in excellent agreement with certified values at the 95% confidence level. This method was also successfully used for the analysis of several real rice and water samples with satisfactory results (90-130% recoveries of added spikes).