摘要
研究了显色剂2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(简称为5-Br-PADAP)与铁(Ⅱ)显色反应条件,在pH=6.0的醋酸-醋酸钠缓冲体系中,采用阳离子表面活性剂溴代十六烷基吡啶增溶增敏。铁(Ⅱ)与显色剂形成的配合物组成为Fe(Ⅱ)∶R=1∶2,络合物具有两个吸收峰,分别位于λ1=556nm与λ2=748nm。选择748nm进行测定,其摩尔吸光系数为ε748=3.3×104L·mol-1·cm-1。铁含量在0—30μg/25mL范围内服从比耳定律。此法用于水样中微量铁的测定,结果准确可靠。
2-（5-Bromo-2-pyridylazo）-5=diethyl-aminophenol（5-Br-PADAP） reacts with Fe（ Ⅱ） in the presence of NaAc-HAc suffer solution（pH is 6.0） and hexadecylpyridinium bromide,a 1 ： 2 stable purple red complex is formed with two absorption wavelengths at 556nm and 748nm. The apparent molar absorption coefficient ε748 is 3.3×10^4L·mol^-1·cm^-1. Beer＇s law is obeyed in the range of 0--30μg/ Fe（ Ⅱ ） per 25mL. The operation is very simple, sensitive, and accurate. The method is applied to determine trace iron in water with satisfactory results.
出处
《光谱实验室》
CAS
CSCD
2008年第2期229-232,共4页
Chinese Journal of Spectroscopy Laboratory
