Universidade Federal da Bahia, Programa de Pós-Graduação Em Química, Campus Universitário de Ondina, Salvador, Bahia, 40170-280, Brazil; Universidade Estadual Do Sudoeste da Bahia, Laboratório de Química Analítica (LQA), Campus de Jequié, Jequié, Bahia, 45206-510, Brazil.
Universidade Federal da Bahia, Programa de Pós-Graduação Em Química, Campus Universitário de Ondina, Salvador, Bahia, 40170-280, Brazil.
Talanta. 2021 Mar 1;224:121893. doi: 10.1016/j.talanta.2020.121893. Epub 2020 Nov 13.
In this study, a method based on direct-immersion single-drop microextraction was developed for the determination of vanadium in water. The detection system uses digital images obtained directly from the solvent drop after the sorption of V(V). The extraction solvent used was the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([CMIM][PF]). The images were obtained directly from the solvent drop, with the aid of a camera. The digital images were stored, and the RGB (red, green, and blue) data were obtained. The data collected by the red channel were used to construct the analytical curve since it showed higher sensitivity compared with green and blue channels. Under optimized conditions, the method presented an enrichment factor of 50 and a limit of detection of 0.6 μg L for 3.5 mL sample volume. The limit of quantification and the relative standard deviation (50.0 μg L) obtained were 1.8 μg L and 4.8%, respectively. Certified reference material (Plankton) was used to assess the accuracy of the method. The simple, fast, efficient, and low-cost procedure was successfully applied to the determination of V(V) in water samples. The proposed method is also following the principles of green chemistry since it uses minimal volumes of samples, reagents, and solvents and yields a small amount of waste.
在这项研究中，开发了一种基于直接浸入单滴微萃取的方法，用于测定水中的钒。检测系统使用 V(V) 吸附后直接从溶剂滴中获得的数字图像。所用的萃取溶剂是离子液体 1-己基-3-甲基咪唑六氟磷酸盐([CMIM][PF6])。直接从溶剂滴中获得图像，借助相机。存储数字图像，并获得 RGB（红、绿、蓝）数据。与绿通道和蓝通道相比，由于红通道显示出更高的灵敏度，因此使用红通道收集的数据来构建分析曲线。在优化条件下，该方法对于 3.5 mL 样品体积，富集因子为 50，检测限为 0.6 μg L。获得的定量限和相对标准偏差（50.0 μg L）分别为 1.8 μg L 和 4.8%。使用认证参考物质（浮游生物）来评估方法的准确性。该简单、快速、高效且低成本的程序成功应用于水样中 V(V)的测定。该方法还遵循绿色化学原则，因为它使用最小量的样品、试剂和溶剂，产生的废物量也很小。
