食品科学 ›› 2011, Vol. 32 ›› Issue (14): 277-280.doi: 10.7506/spkx1002-6630-201114060

• 分析检测 • 上一篇    下一篇

BCA法测定食品中的微量铜

刘 璇,冯志明*   

  1. 湖南师范大学化学化工学院
  • 出版日期:2011-07-25 发布日期:2011-06-18
  • 基金资助:
    湖南省教育科研项目(09C641)

Spectrometric Determination of Trace Copper in Foods by BCA (2,2'-Biquinoline-4,4'-dicarboxylic acid disodium salt) Method

LIU Xuan,FENG Zhi-ming*   

  1. (College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410008, China)
  • Online:2011-07-25 Published:2011-06-18

摘要: 研究BCA(2,2'-联喹啉-4,4'-二甲酸二钠盐)与铜的显色反应,建立测量食品微量铜的光度分析方法。在盐酸羟胺存在条件下,pH11.0缓冲介质中,BCA试剂与铜在物质的量的比为2:1的条件下反应生成的紫色络合物,λmax=562nm,ε562nm=7.72×103L/(mol ·cm),铜含量在0~4.8μg/mL内符合比尔定律;经测定茶叶和海带中的铜含量,结果与原子吸收法的测定结果相符。结果表明:该方法稳定准确,可用于食品中微量铜的测定。

关键词: 铜, 测定, BCA法, 分光光度法

Abstract: The colour reaction between BCA (2,2'-biquinoline-4,4'-dicarboxylic acid disodium salt) and copper was developed for determining trace copper in foods. In the presence of pH 11.0 buffer solution and hydroxylamine hydrochloride, BCA could react with copper (II) to form a purple complex with a ratio of 2:1. The molar absorbance constant was 7.72 × 103 L/(mol ·cm) at 562 nm. The absorbance obeyed Beer s law in the range of 0-4.8μg/mL Cu (Ⅱ). The established method was used for the determination of trace copper in tea and kelp. The determination results are consistent with the results from atomic absorption spectrometry (AAS) method. In conclusion, this method has the advantages of good accuracy, stability and can therefore be applied to the determination of trace copper in foods.

Key words: copper, determination, BCA method, spectrophotometry

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