【摘要】 在弱酸性溶液中,Fe3+-PAR络合物可发生光化学还原反应生成Fe2+-PAR络合物。研究了溶液酸度、光强度、有机酸、PAR溶液浓度对Fe3+-PAR络合物光化学还原反应的影响,并对反应机理作了初步探讨。在pH4.5HAc-NaAc缓冲溶液中,PAR浓度为1.8×10?4mol/L,125W高压汞灯照射15min,Fe3+-PAR络合物的光化学还原反应趋于完全。Fe2+浓度在0.12～3.2mg/L范围内符合比尔定律;检出限为0.025mg/L。更多还原

【Abstract】 Fe3+-4-(2-pyridylazo)resorcinol(PAR)complex undergoes photoreduction in weak acid solution to produce Fe2+-PAR complex.The effects of solution acidity,light intensity,the presence of specific organic acids and PAR concentration on the photoreduction of Fe3+-PAR complex were studied,and the photoreducion mechanism was discussed.The results show that Fe3+-PAR complex in a HAc-NaAc buffer solution(pH 4.5)containing PAR(concentration 1.8×10-4 mol/L)can be transformed into Fe2+-PAR complex completely when subjected to continuous illumination(the high-pressure Hg-lamp,125 W)for 15 minutes.The Beer’s law is obeyed in the range of 0.12-3.2 mg/L of iron(Ⅱ)and the detection limit is 0.025 mg/L.Based on the results,a new photoreduction method has been developed for the determination of iron.更多还原