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4-(2-吡啶偶氮)间苯二酚分光光度法测定奶粉中微量锌的含量的研究
Spectrophotometric Determination of Zinc in Milk Powder by 4-(2-Pyridyazo)-resorcinol
【摘要】 研究了在溴化十六烷基三甲基铵(CTMAB)存在下,4-(2-吡啶偶氮)间苯二酚(PAR)与Zn(Ⅱ)显色反应的适宜条件。结果表明,在pH值为8.0~10.5的范围内,锌与PAR形成稳定的1∶2的橙红色络合物,其最大吸收波长为505nm,试剂的最大吸收波长为425nm,配合物的摩尔吸光系数在505nm处为862×104l·mol-1·cm-1。Zn(Ⅱ)的浓度在0~25μg/25ml范围内符合比耳定律,检出限为0.2μg/25ml。方法用于奶粉中微量锌的测定,结果较好。
【Abstract】 The appropriate conditions for the formation of the comple of zinc with chromagenic reagent 4-(2-pyridylazo)-resorcinol(PAR) in the presence of the cetyltrimethylammonium bromide (CTMAB) have been investigated.The results showed that zinc formed a stable orange-red comlex with PAR in the pH range of pH 8.0~10.5 .The molar ratio of Zn(Ⅱ) to PAR in the complex has been estimated to be 1∶2.The maximum absorption of the reagent is at 425 nm while the maximum absorption of the complex is at 505 nm,with molar absorption of 8.62×104 l·mol-1·cm-1.Beer′s law is obeyed in range of 0~25 μg Zn per 25 ml.The method has been used for the determination of zinc in milk powder with satisfatory results.
【Key words】 zinc; spectrophotometry; 4-(2-pyridylazo)-resorcinol; cetyltrimethylammonium bromide; milk powder;
- 【文献出处】 河北化工 ,HEIBEI CHEMICAL ENGINEERING AND INDUSTRY , 编辑部邮箱 ,1997年04期
- 【分类号】O657.3
- 【被引频次】11
- 【下载频次】162