双波长分光光度法测定青麻果实中锌含量

Determination of Zinc in Abutilon Fruit by Double-wavelength Spectrophotometry

在pH=6.0的六亚甲基四胺缓冲溶液中,Zn^(2+)与二甲酚橙形成红色配合物,以试剂空白为参比,在570nm处褪色,在440nm处生色,实验表明在一定范围内△A=A440-A570与Zn^(2+)浓度呈线性,建立了双波长分光光度法测定青麻果实中Zn^(2+)含量的方法。最佳实验条件下,Zn^(2+)含量在0.1~0.6μg/mL范围内符合Lambert-Bill定律,检出限为1.5×10^(-2)μg/mL。结果表明,方法的相对标准偏差小于5%,加标回收率为95.0%~96.0%。方法简便快速。

A colored coordination complex was formed by Zn2＋ and xylenol orange in pH 6.0 hexamethylenetetramine buffer solution. The color faded at 570 nm and formed at 440 nm. The results show that △A=A440--A570 is linearly related to the Zn2 ＋ concentration within certain range. The double- wavelength spectrophotometry for the determination of Zn2＋ content is established. Lambert-Bill laws were implemented when the Zn2＋ concentration ranged from 0.1 to 0.6 μg/mL. The detection limit was 1.5×10-2 μg/mL. The method, which is simple and accurate, has been applied to the determination of zinc in Abutilon Fruit. The relative standard deviation was less than 5% and the recovery was between 95.0% and 96.0%.