摘要
本文研究了三溴偶氮肿(TBA)与钙、镁的显色反应,结果表明:在平平加存在下,PH10.4硼酸-氢氧化钠缓冲体系中,钙、镁与TBA都形成1:2稳定的紫色络合物,以490nm为参比波长,620nm为测定波长,用双波长分光光度法测得ε_(490-620)^(Ca)=7.21×10~3l·mol^(-1)·cm^(-1),ε_(490-620)^(Ca)=2.55×10~4l·mol^(-1)·cm^(-1),比尔定律范围是0-35μgmg/25ml,0-40μgCa/25ml,无平平加时ε_(490-620)^(Mg)=6.61×10~3l·mol^(-1)·cm^(-1),ε_(490-620)^(Ca)=2.3×10~4。根据有无平平加时测定络合物吸光度的差异,利用公式法求得Ca,Mg含量,方法简便、快速、可靠。
The chromagcnic reaction of calium and magnesium with Tribromo-Arscnazo have been studied.The results show that both of calcium and magnesium with tribromo-Arscnazo form 1 : 2 violet complex at peregal o and PH10.4 buffer medium of H3BO3-NaOH. The rcsallant can be determined by dual-wavelength spectrophotometry with Tribomo-Arscnazo at 490-620nm.The molar absorptirity of the complcxs are 7.21 × 103for Mg and 2.55 × 104for Ca. Without the presence of pcrcgal 0,the molar absorptivity of the complexs are 6.61 × 103for Mg and 2.3 × 104for Ca Beer's law is obeyed in the range of 0 to 35 μg pcr25ml for Mg,and 0-30μg for Ca. At the Same time,based on the presence o pcrgal 0 or no pcrcgal O,dctcrmi-natc complex different absorption.This Calculate content of Ca and Mg method is simple,reliable and accurate.
出处
《干旱环境监测》
1990年第2期76-80,共5页
Arid Environmental Monitoring
关键词
双波长分光光度法
钙、镁联合测定
水样
Dual-wavelength spcctrophotometry de e ation. for Ca and Mg,Water Sample
