National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
Food Chem Toxicol. 2011 Oct;49(10):2548-56. doi: 10.1016/j.fct.2011.06.065. Epub 2011 Jul 3.
Cloud point extraction method has been developed for preconcentration of trace quantities of zinc (Zn) in aqueous extract of medicinal plants and blood samples of liver cancer patients using flame atomic absorption spectrometry. The Zn in aqueous extracts of medicinal plants (MPs) was complexed with 2-methyl-8-hydroxyquinoline (quinaldine) and 1-(2-pyridylazo)-2-naphthol (PAN) separately and entrapped in a non-ionic surfactant Triton X-114. After centrifugation, the surfactant-rich phase was diluted with 0.25mL acidic ethyl alcohol. The multivariate strategy was applied to estimate the optimum values of experimental variables (pH, time temperature, ligands and surfactant concentrations). Interactions between analytical factors and their optimal levels were investigated by two level factorial designs. Student's t-test on the results of factorial design with 16 runs for Zn extraction, demonstrated that the factors, ligands concentrations, pH and temperature were statistically significant. The accuracy was assessed by analysis of certified reference materials, namely, BCR 101 (spruce needles), Clincheck control-lyophilized human whole blood. Enhancement factor of 30 and 26 were achieved for the preconcentration of Zn by 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2), respectively. The relative standard deviation for six replicate determinations of Zn at 10μg/L level using 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2) were <4% and >5%, respectively.
已经开发出浊点萃取方法，用于使用火焰原子吸收光谱法在中草药水提物和肝癌患者的血液样品中预浓缩痕量锌（Zn）。中草药（MPs）水提物中的 Zn 分别与 2-甲基-8-羟基喹啉（喹哪啶）和 1-（2-吡啶偶氮）-2-萘酚（PAN）络合，并包埋在非离子表面活性剂 Triton X-114 中。离心后，用 0.25mL 酸性乙醇稀释富含表面活性剂的相。应用多元策略来估算实验变量（pH、时间、温度、配体和表面活性剂浓度）的最佳值。通过两水平析因设计研究了分析因素之间的相互作用及其最佳水平。对 16 次运行的因子设计结果进行学生 t 检验，表明配体浓度、pH 和温度等因素具有统计学意义。通过分析认证参考物质（即云杉针 BCR 101 和冻干人全血 Clincheck 对照品）来评估准确性。用 2-甲基-8-羟基喹啉（L1）和 1-（2-吡啶偶氮）-2-萘酚（L2）分别对 Zn 进行预浓缩时，可获得 30 和 26 的增强因子。使用 2-甲基-8-羟基喹啉（L1）和 1-（2-吡啶偶氮）-2-萘酚（L2）在 10μg/L 水平下对 Zn 进行 6 次重复测定的相对标准偏差分别小于 4%和大于 5%。
