Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
Engineering Faculty, Near East University, Nicosia 99138, Mersin 10, North Cyprus, Turkey.
Anal Methods. 2023 Aug 31;15(34):4321-4330. doi: 10.1039/d3ay01010d.
In this study, a new homogeneous liquid-liquid microextraction method using a deep eutectic solvent has been developed for the extraction of Cu(II) and Pb(II) ions in dairy products. Initially, the deep eutectic solvent was synthesized using choline chloride and -chlorophenol and used as the extraction solvent. The synthesized solvent was soluble in milk at 70 °C and its separation from the sample was performed by decreasing the temperature. By cooling, a cloudy solution was formed due to the low solubility of the solvent at low temperatures. On centrifugation, the fine droplets of the solvent containing the analytes settled at the bottom of the tube by sedimentation. The enriched analytes were determined by flame atomic absorption spectrometry. The effect of some important parameters such as the amount of protein precipitating agent , complexing agent amount, extraction solvent volume, salt addition, pH, and temperature on the extraction efficiency of the method was studied and optimized. Under the optimal conditions, the linear ranges of the method for Cu(II) and Pb(II) ions were obtained in the ranges of 0.10-50 and 0.50-50 μg L with detection limits of 0.04 and 0.18 μg L, respectively. The repeatability of the developed method, expressed as relative standard deviation, was determined to be 3.2 and 3.9% for Cu(II) and Pb(II) ions, respectively. Finally, by determining the concentration of Cu(II) and Pb(II) ions in milk, doogh, and cheese samples, the feasibility of the method was successfully confirmed with the extraction recoveries of 95.9 and 92.1% for Cu(II) and Pb(II) ions, respectively.
在本研究中，开发了一种使用深共晶溶剂的新的均相液-液微萃取方法，用于萃取乳制品中的 Cu(II)和 Pb(II)离子。首先，使用胆碱氯化物和 -氯苯酚合成深共晶溶剂，并将其用作萃取溶剂。合成的溶剂在 70°C 下可溶于牛奶中，通过降低温度将其与样品分离。通过冷却，由于溶剂在低温下的溶解度低，形成了混浊的溶液。在离心时，含有分析物的溶剂的细小液滴由于溶剂在低温下的高溶解度而沉降到底部。通过火焰原子吸收光谱法测定富集的分析物。研究并优化了一些重要参数对方法萃取效率的影响，如蛋白质沉淀剂的量、络合剂的量、萃取溶剂的体积、盐的添加、pH 值和温度。在最佳条件下，Cu(II)和 Pb(II)离子的方法线性范围分别为 0.10-50 和 0.50-50 μg L，检测限分别为 0.04 和 0.18 μg L。开发方法的重复性，以相对标准偏差表示，Cu(II)和 Pb(II)离子分别为 3.2%和 3.9%。最后，通过测定牛奶、都古和奶酪样品中 Cu(II)和 Pb(II)离子的浓度，成功地证实了该方法的可行性，Cu(II)和 Pb(II)离子的萃取回收率分别为 95.9%和 92.1%。
