摘要
本文系统地研究了4-(2-吡啶偶氮)间苯二酚(PAR)与铁(Ⅱ)的显色反应、试验表明,在pH9.0~10.3范围内Fe(Ⅱ)与PAR形成稳定的红色配合物,配合物在502nm和716nm处有2个吸收峰,其表观摩尔吸光系数分别为4.8×104L·mol-1·cm-1和2.3×104L·mol-1·cm-1,配合物组成为Fe:PAR=1:3,表观稳定常数为4.2×1015。在716nm处,铁浓度在0~1.8μg/mL范围内服从比耳定律,用本法直接测定食品中微量铁,结果令人满意。
The colour reaction of iron (Ⅱ) with 4- (2-pyridylazo)-resorcinol (PAR) has been studied.Iron (Ⅱ) reacts with PAR at pH9.0~ 10. 3 to form a stable 1: 3 chelate in aqueous solution.The apparent molar absorptivity of this chelate is 4. 8 ×104L. mol-1·cm-1 (502nm ) and 2. 3 ×104L. mol-1·cm-1(716nm). Beer's law is obeyed in the range of 0~1.8μg/mL for iron (716nm). The method has been applied to the determination of trace iron in food with satisfactory results.
出处
《浙江师大学报(自然科学版)》
1997年第4期66-68,共3页
Journal of Zhejiang Normal University(Natoral Sciences)