【摘要】 研究了新显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸(简称CTZDBA)与铁的显色反应。结果表明,在pH4.0的HAc-NaAc缓冲溶液中,CTZDBA与Fe(Ⅲ)形成稳定的络合比为2∶1的紫红色络合物,最大吸收波长为560nm,络合物的表观摩尔吸光系数为2.21×104L.mol-1.cm-1,Fe(Ⅲ)质量浓度在(0～0.8)mg/L范围内符合比尔定律。所拟方法不经分离直接测定纯铝和铝合金样品中微量的铁,测定结果与认定值相符。更多还原

【Abstract】 The conditions of color reaction of a new reagent 2-(5-carboxy-1,3,4-triazolylazo)-5-di-ethylamino-benzoicacid(CTZDBA)with iron(Ⅲ)was studied.The results showed that the CTZDBA reacts with iron(Ⅲ)to form a 2:1 stable purple red complex in the buffer solution of HAc-NaAc with pH 4.0.The maximum absorption wavelength is at 560 nm.The apparent molar absorptivity is 2.21×10 4 L·mol-1·cm-1.Beer’s law is obeyed in the range of(0～0.8)mg/L for Fe(Ⅲ).The method has been used for the direct determination of iron in aluminium alloys and pure aluminium.The results compare favourably with the certified values.更多还原