微波辅助消解紫外分光光度法测定面制品中铝含量

Determination of Aluminum in Flour Products with Microwave Assisted Digestion and Ultraviolet Spectrophotometer

面制品受自然因素和生成加工环节影响,铝元素含量逐步升高,它对人体神经系统有一定损害作用。本文对面制品试样采用微波辅助、硝酸-硫酸消解,浓硫酸进行赶酸处理,以铬天青S为显色剂,在乙酸–乙酸钠缓冲体系进行显色反应,结合紫外分光光度准确检测铝的含量。检测方法的相对标准偏差≤3.06%（n=6）,加标回收率在98%~101%之间（n=4）,满足实际检测分析要求。应用表明,微波辅助进行面制品试样处理,缩短了时间,减少了强酸的使用量,方法高效便捷、灵敏度高、结果准确可靠。

Aluminum is harmful to human neural system and its content is continuously increasing in flour products due to natural resources and food processing. In this paper, samples are digested by the mixture of HNO3 and H2SO4 with microwave-assisting, and treated by concentrated sulfuric acid to remove the left acid. The determination is carried out with ultraviolet speetrophotometer using chromeazurol S as chromogenic agent in acetic acid-sodium acetate buffer solution. The relative standard deviation （RSD） is less than 3.06% （ n = 6） with the spiked standard samples recovery 98% - 101% （ n = 4）, which meets the requirements of practical tests and analyses. Application in real sample determination indicates that less time is consumed and acid usage is reduced in microwave-assisted flour product sample treatment. This new approach is simple, convenient, sensitive and reliable.