ゼフィラミンの存在における鉄(III)-クロムアズロールS錯体の吸光光度法による検討(報文)

概要

論文の詳細を見る
The acid dissociation constants of Chromazurol S (CAS, H4L) in the presence of 5.42×10-3M zephiramine (tetradecyldimethylbenzylammonium chloride, ZCl) and 0.1M ammonium chloride were pK2'=0.3, pK3'=4.0 and pK4'=12.3 at 25°C. The presence of zephiramine enhanced the acid dissociations of carboxyl groups in CAS but it decreased that of hydroxyl group. Iron (III) with an excess CAS mainly formed a 1 : 1 complex (FeHL) at pH below 3, but formed in the presence of zephiramine a 1 : 2 complex [Fe(HLZ)2-] with an absorption maximum at 634 mμ increasing the photometric sensitivity. The formation of the complex concluded in 8.56×10-4MCAS and 5.42×10-3M zephiramine at pH 3 and Beer's law held for 0.044 ppm of iron (III) with molar absorptivity at 634 mμ 1.5×105.
社団法人日本分析化学会の論文