2-(2-噻唑偶氮)-5-二甲氨基苯甲酸与铁(Ⅱ)显色反应的研究及其应用  

Colour Reaction of Iron(Ⅱ) With 2-(2-Thiazolylazo)-5-dimethylaminobenzoic Acid and Its Application

作　　者：朱有瑜[1] 陈前六 

机构地区：[1]杭州大学化学系,杭州310028

出　　处：《分析化学》1993年第7期815-817,共3页Chinese Journal of Analytical Chemistry

摘　　要：本文研究了在乙醇介质中,2-(2-噻唑偶氮)-5-二甲氨基苯甲酸(TAMB)与铁(Ⅱ)的显色反应。试验表明,在pH5.2～6.3范围内Fe(Ⅱ)与TAMB形成稳定络合物。最大吸收峰位于580nm处,表观摩尔吸光系数为7.7×10~4L·mol^(-1)·cm^(-1)。络合物组成比为Fe(Ⅱ):TAMB=1:2,其表观不稳定常数为3.06×10^(-11),铁浓度在0～12μg/25ml范围内符合比尔定律。用本方法直接测定铝合金中的铁及人发中的微量铁,结果满意。A simple, sensitive and selective method for the spectrophotometric determination of iron has been developed. Iron(Ⅱ ) reacts with 2-(2-thiazolylazo)-5-dimethylaminobenzoic acid (TAMB) to form a stable complex in aqueous alcohol solution. Fe( Ⅱ) can form a 1 : 2 complex with ligand in the (CH2)6N4-HCl medium at pH 5. 5. The apparent molar absorptivity of Fe( Ⅱ)-TAMB is 7. 7 × 104L· mol-1 · cm-1 at 580 nm. Beer's law is obeyed in the range of 0-12μg/25 ml for iron. The colour of aqueous solution is stable for 24 h. Thiourea, sodium fluoride and tetraethylenepentamine are used to increase the selectivity of the method. The proposed method has been used for the determination of trace iron in aluminum alloys and human hair with satisfactory results. The recovery of Fe is in the range of 98. 3%-101. 6%.

关 键 词：铁 光度法 TAMB 显色剂 

分 类 号：O614.811[理学—无机化学]