双氧水氧化双指示剂催化褪色光度法测定痕量铁(Ⅲ)  

Catalytic fading spectrophotometric determination of trace iron(Ⅲ) with dual-indicator oxidized by hydrogen peroxide

作　　者：柴红梅[1] 马荣萱[1] 孙雪花[1] 杨啟钧 

机构地区：[1]延安大学化学与化工学院陕西省化学反应工程重点实验室,陕西延安716000

出　　处：《冶金分析》2016年第3期69-72,共4页Metallurgical Analysis

基　　金：陕西省教育厅重点实验室基金(No.14JS111);延安大学引导项目基金(YD2015-08)

摘　　要：在HNO_3介质中,痕量铁(Ⅲ)能催化H_2O_2氧化罗丹明B和亚甲基蓝的褪色反应,通过测量555nm和663nm处催化和非催化体系吸光度的变化,利用铁(Ⅲ)的浓度与两波长处吸光度差值的和呈线性关系,建立了双波长双指示剂催化动力学光度法测定痕量铁(Ⅲ)的新方法。实验表明:线性回归方程为ΔA=0.064 85ρFe3+(μg/L)+0.439 6,相关系数r=0.998 3。方法的线性范围为2.0~20.0μg/L,检出限为0.185μg/L。实验方法用于雨水、河水和自来水中痕量铁(Ⅲ)的测定,测定值与原子吸收光谱法(AAS)基本一致,相对标准偏差(RSD,n=6)在0.38%~0.53%之间,加标回收率为99%~102%。The fading reaction of rhodamine B and methylene blue oxidized by hydrogen peroxide could be catalyzed by trace iron(Ⅲ)in HNO_3 medium.The absorbance change of catalytic system and non-catalytic system was measured at 555 nm and 663 nm,respectively.The concentration of iron(Ⅲ) showed good linearity to the sum of the absorbance difference at two wavelengths.Thus,a new determination method of trace iron(Ⅲ) by catalytic kinetic spectrophotometry was established with dual-wavelength and dual-indicator.The results showed that the linear regression equation wasΔA=0.064 85ρFe^(3+)(μg/L)+0.439 6with correlation coefficient of r=0.998 3.The linear range of method was 2.0-20.0μg/L.The detection limit was 0.185μg/L.The proposed method was applied to the determination of trace iron(Ⅲ)in rain water,river water and tap water.The results were consistent with those obtained by atomic absorption spectrometry(AAS).The relative standard deviations(RSD,n=6)were between 0.38% and 0.53%.The recoveries were between 99% and 102%.

关 键 词：双波长 双指示剂 催化褪色光度法 罗丹明B 亚甲基蓝 铁 

分 类 号：O657.3[理学—分析化学]