表面活性剂增敏光度法测定海产品中的微量镉(Ⅱ)

DETERMINATION OF MICRO Cd( n ) IN THE SEA PRODUCT BY SURFACE ACTIVE AGENT INCREASE SENSITIVITY SPECTROPHOTOMETRY

在六次甲基四胺缓冲溶液(pH=6.3)存在下,以二甲酚橙(XO)作显色剂,表面活性剂十六烷基三甲基溴化铵(CTMAB)对镉(Ⅱ)与XO的显色反应具有增敏作用,形成的镉(Ⅱ)-XO-CTMAB三元配合物呈紫色,配合物的最大吸收波长为605nm,表观摩尔吸光系数为2.04×10~5 L/(mol.cm)。镉(Ⅱ)的浓度在0～8μg(25mL)内符合比耳定律,线性回归方程为A=0.025c+0.2,检出限为5×10^(-4)μg/mL。该法用于海产品中微量镉的测定,测定结果的相对标准偏差为0.104％,回收率为91.0％。

In the presence of hexamethylene tetramine buffer solution (pH=6.3),the color reaction of Cd(Ⅱ) with xylenol orange(XO) in the presence of cetyl trimethyl ammonium bromide( CTMAB) was sensitized, the stationary ternary complex Cd(Ⅱ)-XO-CTMAB is purple, the maximum absorption of the complex is at 605 nm, the apparent molor absorptivity of the complex is 2.04μ105L/(mol.cm). Beer's law was obeyed for Cd(Ⅱ) in the range of 0 ~ 8μg/(25 mL) , the linear regression equation is A -0. 025c +0. 2, the detection limit is 5 ×10-4μg/mL. For the determination of Cd(Ⅱ) in the sea product, the relative standard deviation is 0. 104% , the recovery is 91. 0% .