1-(2-吡啶偶氮)-2-萘酚显色法测定烟草中的铜

Determination of Copper in Tobacco by Spectrophotometry Using 1-(2-Pyridine azo)-2-naphthol as a Color Reagent

摘要: 研究了1-(2-吡啶偶氮)-2-萘酚显色法测定烟草中的铜。在pH=4.0的HAc-NaAc缓冲介质中,Cu²⁺与1-(2-吡啶偶氮)-2-萘酚形成稳定的配合物,该配合物在λ_max=552nm处有最大吸收。铜含量在0~15μg/25mL范围内该配合物的吸光度与铜含量的关系符合比耳定律。用于测定烟草样品中的铜含量,回收率为97.89%~101.35%,灵敏度和选择性都能达到要求,测定结果与原子吸收测定方法的相对标准偏差在1.7%~2.6%之间,无显著差异。

Abstract: The determination of copper in tobacco by coloration using 1-(2-pyridine azo)-2-naphthol as a color reagent was studied.In the HAc-NaAc buffer medium with a pH value of 4.0, a stable complex was formed by reaction of Cu²⁺ with 1-(2-pyridine azo)-2-naphthol, and the maximum absorption of the complex was at wavelength of 552nm.When the concentration of copper was in the range of zero to 15μg per 25 milliliter, the relationship between the absorption of the complex and the concentration of Cu²⁺ observed the Beer's law.Being used for determining the content of copper in tobacco, the recovery of copper standard was from 97.89%to 101.35%, and the requirements of sensitivity and selectivity were fulfilled.The relative standard deviation between this method and the atomic absorption was from 1.7% to 2.6%.No significant difference was found.