铜试剂测定溶液铜离子浓度分光光度法的改进

Improvement of spectrophotometric method for determination of copper ions concentration in solution by copper reagent

通过在显色反应体系中加大乙醇的使用量,改进了二乙基二硫代氨基甲酸钠测定溶液Cu^(2+)溶度的方法,使用NH3-NH4Cl缓冲溶液保证了反应体系稳定在pH=8~10,铜试剂与Cu2+完全显色的摩尔比为3∶1,显色反应生成的橘黄色物质稳定均一的存在于反应体系中,不需要萃取,可直接进行分光光度法的检测,在波长λ=452nm处的有效地检测范围为0.011~0.071mmol·L-1,符合朗伯-比尔定律,线性相关系数是0.9993。以柠檬酸铵作为掩蔽剂,杂质金属离子在一定浓度范围内的干扰可以得到消除。该方法避免了使用CCl4等有毒萃取溶剂,也简化了操作步骤,提高了测定的准确度,使得检测方法更加绿色快捷高效。

By increasing the amount of ethanol used in the color reaction system, the method for determining the solubility of copper ions in solution by sodium diethyldithiocarbamate was improved. The NH3-NH4 Cl buffer solution was used to ensure the stability of the reaction system at pH=810. The molar ratio of the copper reagent to the complete coloration of the copper ion is 3∶1, and the orange substance formed by the color reaction is stable and uniform in the reaction system, and does not require extraction, and can be directly detected by spectrophotometry at the wavelength λ=452 nm. The effective detection range is 0.0110.071 mmol·L^-1, which is in accordance with Lambert-Beer law, and the linear correlation coefficient is 0.9993. With ammonium citrate as a masking agent,interference of impurity metal ions in a certain concentration range can be eliminated. The method avoids the use of toxic extraction solvent such as CCl4, simplifies the operation steps, improves the accuracy of the measurement, and makes the detection method greener, faster and more efficient.