补益药中微量铜的微波消解光度法测定

Determination of Micro-copper in Chinese Herb by Spectrophotometry with Microwave Digestion

[目的]为中药材中微量Cu的测定和样品处理建立一种新的理论和方法。[方法]研究了有机试剂硝基磺酚C与Cu(Ⅱ)的光谱变化、反应条件、表面活性剂及共存物质的影响,并研究了样品处理和测定的方法。[结果]在pH值2.8的Britton-Robinon缓冲介质中,紫红色的硝基磺酚C能与Cu(Ⅱ)形成蓝色配合物,λmax为665nm,比试剂本身红移115nm。Cu含量在0～1.28μg/ml范围内符合Beer定律,表观摩尔吸光系数为2.13×104L/(mol.cm),乙醇存在有增敏作用。[结论]建立了微波消解样品,微量Cu测定的光度新方法。建立的方法简便,灵敏度高,用于中草药中Cu含量的测定,取得了满意的结果。

[Objective] The aim was to build a new theory and methods to determine the trace copper in Chinese herb.[Method]The microwave digestion condition,the change of spectrum,the surfactants and the coexistive ions,as well as the methods to treat and determine the samples were studied.[Result]The purplish red dyes Nitrosulfophenol C could bind with Cu（Ⅱ）and form blue complex in Britton-Robinson buffer at pH 2.8,which presented a maximum absorption of 665 nm with 115 nm of red shift compared to Nitrosulfophenol C itself.The molar absorptivity was 2.13×104 L/（mol·cm）.Beer＇s law was obeyed by Cu（Ⅱ）in the range of 0-1.28 μg/ml.The absorbance improved with the presence of alcohol.[Conclusion]This method was simple and sensitive,which has been used for the detemination of Cu（Ⅱ）in Chinese herb with satisfactory results.