Marmara University, Faculty of Arts and Sciences, Chemistry Department, Istanbul, 34722, Turkey.
J AOAC Int. 2021 Jun 12;104(3):645-649. doi: 10.1093/jaoacint/qsaa169.
The natural concentration of trace elements in water and soil depends on the geological, geomorphological, and climate characteristics of the region. The rapid increase of technology in recent years has increased concentrations of trace elements in nature.
Separation and enrichment methods are needed to detect trace amounts of heavy metals that cannot be detected due to the detection limit of the instruments or the matrix effect in samples. Recently, low hazard solvents compatible with green chemistry have been used in preconcentration/separation studies of Cd(II).
Switchable solvent-based liquid phase microextraction is an environmentally-friendly, simple, and fast procedure for the determination of Cd(II) ions in environmental samples combined with flame atomic absorption spectrometry (FAAS).
The switchable polarity solvent was prepared with N,N-dimethyl-n-octylamine. 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was used as the complexing agent. Important parameters such as pH, amount of switchable polarity solvent and NaOH, as well as ligand and sample volume, all of which might affect the microextraction efficiency were optimized. Under optimal experimental conditions, linear range was found to be between 5 and 500 µg/L. The limit of detection, preconcentration factor, and relative standard deviation were 0.89 μg/L, 150, and 3.2%, respectively.
The accuracy of our method was confirmed by the analysis of certified reference material SPS-WW1 Batch 106 (Waste Waters). The developed procedure was successfully applied to determine the cadmium contents of environmental water samples. We believe that this environmentally-friendly method will be useful in detecting Cd(II) ions in water samples.
水和土壤中微量元素的自然浓度取决于该地区的地质、地貌和气候特征。近年来，技术的快速发展增加了自然界中微量元素的浓度。
需要分离和富集方法来检测由于仪器检测限或样品基质效应而无法检测到的痕量重金属。最近，与绿色化学兼容的低危害溶剂已用于 Cd(II)的预浓缩/分离研究。
基于相转移的液-液微萃取是一种环境友好、简单、快速的程序，可与火焰原子吸收光谱法（FAAS）结合用于测定环境样品中的 Cd(II)离子。
用 N,N-二甲基-N-辛基胺制备可切换极性溶剂。2-(5-溴-2-吡啶偶氮)-5-(二乙氨基)苯酚用作络合剂。优化了 pH 值、可切换极性溶剂和 NaOH 的用量、配体和样品体积等重要参数，这些参数都可能影响微萃取效率。在最佳实验条件下，线性范围为 5 至 500μg/L。检测限、预浓缩因子和相对标准偏差分别为 0.89μg/L、150 和 3.2%。
通过对认证参考物质 SPS-WW1 Batch 106（废水）的分析，证实了我们方法的准确性。所开发的程序成功地应用于测定环境水样中的镉含量。我们相信，这种环保方法将有助于检测水样中的 Cd(II)离子。
