摘要
本文研究了在乙醇存在下，铁（Ⅲ）与铬天青Ｓ和溴化十六烷基三甲铵的高灵敏显色反应。在ｐＨ５．１～６．８的乙酸－乙酸铵缓冲介质中，配合物吸光度最大且稳定，最大吸收波长为６４６ｎｍ，表观摩尔吸光系数为２．４２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，铁（Ⅲ）量在０～０．１４ｍｇ·Ｌ－１范围内遵守比耳定律。在氟化钠的存在下，方法具有良好的选择性，直接应用于水样中微量铁的测定，结果满意，相对标准偏差＜５．２％，回收率在９５．６％～１０２．
The colour reaction of Fe (Ⅲ)with chromazurol S and CTMAB in the presence of ethy1 alcohol is spectrophotometrically studied. In a medium of pH5.1～6.8 HAcNH4 Ac,the absorption of the complex reaches maximum and becomes stable with a maximum absorption at 646 nm,and its apparent molar absorptivity is 2.42×105L·mol-1·cm-1.Beer law is obeyed in the range of 0￣0.14 mg·L-1 Fe(Ⅲ).In the presence of sodium fluoride,the method is highly selective.It has been used to direct determine trace iron in water sample with relative standard deviation of less than 5.2% and recover of 95.6%～102.4%.
关键词
铁
铬天青S
乙醇
分光光度法
水
iron
chromazurol S
CTMAB
ethy1 alcohol
spectrophotometric:water
