牛奶中微量三聚氰胺的分光光度法检测

Detect melamine content in milk with spectrophotometer

奶粉用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），用2，6-二氯靛酚钠为显色剂对牛奶中三聚氰胺进行分光光度法检测。对不同的入射波长、显色剂用量、pH值、显色时间、温度进行了条件实验。结果表明，采用2，6-二氯靛酚钠为显色剂，在25qC显色10min，在634nm有最大吸收。测定范围为40～800／,zg／mL，线性相关系数r=0．9989，加标回收率为92．66％-97，84％，RSD为0．45％-1．43％。

With 0.1% trichloroacetic acid and 2% lead acetate solution to eliminate the interfering sub- stances in the sample （mainly protein） , and choose 2,6-dicbloro-indopbenol sodium as chromogenic rea gent for spectrophotometric method detection＇of melamine in milk. For different incident wavelength,color dosage,pH, color of time and the temperature were test. The results showed that 2,6-dichlorophenol indo phenol sodium as chromogenie reagent, at 25 ℃, color 10 rain, at 634 nm had a maximum absorption. De termination range was 40 - 800 μg/mL, the linear correlation coefficient r = 0. 998 9, the recovery rate was 92.66% - 97.84% ,RSD was 0.45% - 1.43%.