Department of Chemistry, University of Chittagong, Chittagong, Bangladesh.
Chemosphere. 2013 Jan;90(2):366-73. doi: 10.1016/j.chemosphere.2012.07.029. Epub 2012 Aug 22.
A spectrophotometric procedure for the simultaneous determination of zinc(II) and copper(II) in a mixture using diethyldithiocarbamate (DDTC) as ligand has been described. Complexes formed with DDTC was extracted with CHCl(3)/CCl(4) and the absorbance was measured at 435 nm which is equivalent of Cu(II) in sample only as Zn(DDTC)(2) has no absorption. Zinc measurement is based on the quantitative displacement of zinc from Zn(DDTC)(2) by Cu(II) with the addition of excess copper(II) to the extract. The absorbance is measured again where additional absorbance is equivalent to zinc. The molar absorptivity and sandall's sensitivity at this wavelength are 2.86×10(5) mol(-1) L cm(-1) and 3.076 ng cm(-2), respectively. Reproducibility with in 4% and detection limits of 0.29 μg mL(-1) was obtained. Linear calibration range was 0.2-14 μg mL(-1) for zinc and 0.2-12 μg mL(-1) for copper with the regression coefficient (r(2)) 0.998 for each. In the presence of a suitable masking agent (EDTA) very good selectivity was achieved. The method was extended to the determination of zinc and copper in a number of environmental water and soil samples, biological, pharmaceutical, fertilizer and food samples.
一种使用二乙基二硫代氨基甲酸盐 (DDTC) 作为配体的分光光度法，用于同时测定混合物中锌(II)和铜(II)的含量。与 DDTC 形成的配合物用 CHCl(3)/CCl(4) 萃取，在 435nm 处测定吸光度，这仅相当于样品中的 Cu(II)，因为 Zn(DDTC)(2)没有吸收。锌的测量是基于定量置换锌从 Zn(DDTC)(2)与 Cu(II)的加入过量的铜(II)萃取。再次测量吸光度，其中额外的吸光度相当于锌。在这个波长下的摩尔吸光率和桑德尔的灵敏度分别为 2.86×10(5) mol(-1) L cm(-1)和 3.076ng cm(-2)。在 4%的重复性和 0.29μg mL(-1)的检测限下获得了良好的结果。锌的线性校准范围为 0.2-14μg mL(-1)，铜的线性校准范围为 0.2-12μg mL(-1)，每个回归系数 (r(2)) 均为 0.998。在适当掩蔽剂 (EDTA) 的存在下，实现了非常好的选择性。该方法已扩展用于测定环境水样和土壤、生物、药物、肥料和食品样品中的锌和铜。
