分光光度法测定面粉中三聚氰胺

研究的目的是寻找一个采用分光光度法测定三聚氰胺含量的方法。对不同的显色剂、吸收波长、显色剂用量、pH值、显色时间、温度等进行了条件试验。结果表明,采用2,6-二氯酚靛酚钠-丙酮显色剂,在20～30℃,显色15min,在634nm条件下有最大吸收。测定范围为40μg/mL～800μg/mL,线性相关系数r0.9986。面粉中的三聚氰胺用0.1%三氯乙酸溶液和2%乙酸铅溶液消除样品中的干扰物质（主要是蛋白质）,加标回收率为95.59%～98.64%。该方法检测灵敏度、准确度及精密度完全满足日常检测要求,且简便可行,设备价廉。

Spectrophotometric Determination of Melamine in Flour

The objective of this study was to develop a spectrophotometric method for the quantitative determination of melamine. The Spectrophotometric method for the determination of melamine based on chromogenic agent, absorption wave length, dosage of chromogenic agent, pH value, chromogenic time, chromogenic temperature was described in this paper. The results indicated that the linear relationship kept in the range of 40 μg/mL - 800 μg/mL, with a correlation coefficient r = 0. 998 6 at λmax = 634 nm under 20 -30℃ for 15minutes using. 2,6 - dichlorophenol indophenol sodium as chromogenic agent. The sensitivity and method was tested to determine the level of melamine, using a in flour. The recovery value was 95.59% -98.64%. Flour in melamine solution with 0.1% trichloroacetic acid and 2% lead acetate solution to eliminate the interference of the sample material （mainly protein）. The accuracy and precision of this method can meet routing detection with convenient feasibility and low facility cost.