Abstract：In the present paper, an absorbance ratio-derivative method for the simultaneous determination of copper(Ⅱ) and chromium(Ⅲ) was proposed. In the HAc-NaAc buffer solution at pH 5.7 with heating, Cr3+ or Cu2+ with CAS and CTMAB formed a blue ternary complex. The molar absorptivities of Cr(Ⅲ)-CAS-CTMAB and Cu(Ⅱ)-CAS-CTMAB were 2.52×105 L·mol-1·cm-1 and 1.01×105 L·mol-1·cm-1 respectively. Beer’s law was obeyed in the range of 0.08-1.2 μg·mL-1 for Cu(Ⅱ) and 0.05-0.52 μg·mL-1 for Cr(Ⅲ). The detection limits of Cu(Ⅱ) and Cr(Ⅲ) are 0.014 μg·mL-1and 0.013 μg·mL-1 respectively. This method was applied to the determination of Cu(Ⅱ) and Cr(Ⅲ) in surrounding water with satisfactory results.
Key words：Absorbance ratio-derivative method;Simultaneous determination;Copper(Ⅱ);Chromium(Ⅲ);Chrome azurol S
[1] XU Jia-liang, TAN Xiao-dong, JIANG Xiang-dong(徐嘉凉，汤晓东，江向东). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 1999, 19(4): 581. [2] WANG Xu-zhen, et al(王旭珍，等). Chinese J. Anal. Chem.(分析化学)，2001, 29(8): 907. [3] LIANG Guo-dong, et al(梁国栋，等). Physical Testing and Chemical Analysis, Part B: Chemical Analysis(理化检验·化学分册)，2000, 36(12)：555. [4] GAO Wen-ling, et al(高文玲，等). Physical Testing and Chemical Analysis, Part B: Chemical Analysis(理化检验·化学分册)，2002, 38(6): 313. [5] XIE Wei-xin(谢维新). Journal of Guangxi University for Nationalities(Natural Science Edition)(广西民族学院学报·自然科学版)，1997, 3(2): 153. [6] Hernandez F H, Escriche J M. Analyst, 1984, 109(2): 1585.
