镉与DBON-PF显色反应的研究及应用

COLOR REACTION OF CADMIUM(Ⅱ) WITH DBON-PF AND ITS APPLICATION

研究了镉与ＤＢＯＮ－ ＰＦ 显色反应的条件－ 在ｐＨ ９ 的硼砂－ 硼酸缓冲溶液中，有ＣＴＭＡＢ存在下，镉与ＤＢＯＮ－ ＰＦ形成蓝紫色络合物，最大吸收波长为６１０ ｎｍ ，表观摩尔吸光系数为２ ．６４ ×１０５ Ｌ·ｍｏｌ－ １·ｃｍ － １ ，络合物的配合比为Ｃｄ（ Ⅱ）∶ＤＢＯＮ－ ＰＦ∶ＣＴＭＡＢ＝ １∶１∶２ ，镉量在０ ～０ ．１６ μｇ／ｍＬ 符合比耳定律－ 通过巯基棉柱富集、分离，除去大量的干扰离子，本法灵敏度高，稳定时间长，能应用于环境水样和废水中微量镉的测定－ 图１ ，表１ ，参６－

The conditions of the color reaction of Cd(Ⅱ) with 4,5 di bromo 2 nitro phenylfluorone(DBON PF) were investigated.The blue complex was formed in a medium of boric acid borax buffer of pH 9 under the presence of ectyltrimethylammonium bromide(CTMAB).The maximum absorption lies at the wavelength of 610 nm,with a apparent molar absorptivity of 2.64×10 5 L·mol -1 ·cm -1 .The composition ratio of Cd(Ⅱ) to DBON PF and CTMAB is 1∶1∶2.Beer's law is obeyed in the concentration range of 0～4 μg of Cd(Ⅱ) in a volume of 25 mL. Interference from other metal ions can be separated by sulfhydryl cotton.The method possesses the advantages of high sensitivity and longly stabile time.The proposed method had been applied to the determination of cadmium in river water and waste water with satisfactory results.1fig.,1tab.,6refs.