PVA/明胶协同Fe^(3+)-SCN^--RhB高灵敏缔合体系光度法测定铁的研究  

Spectrophotometric determination of iron in complex high sensitive system of Fe^(3+)-SCN^-—Rhodamine B with PVA and gelatin cooperation

作　　者：王晓玲[1] 张萍[1] 陈燕[1] 

机构地区：[1]咸阳师范学院化学与化工学院,陕西咸阳712000

出　　处：《应用化工》2012年第12期2168-2170,共3页Applied Chemical Industry

基　　金：陕西省科技厅科研项目(2012JQ2014);咸阳师范学院专项科研基金项目(11XSYK310)

摘　　要：在硫酸介质中,在聚乙烯醇和明胶的共同作用下,铁(Ⅲ)与硫氰酸根离子形成的络阴离子能与罗丹明B形成蓝色离子缔合物,据此建立了测定痕量铁的高灵敏光度分析方法。缔合物的最大吸收波长为620 nm,线性回归方程为y=0.924x+0.281 3,相关系数为0.999 4,表观摩尔吸光系数为3.38×106L.(mol.cm-1),检出限为0.025μg/L,铁(Ⅲ)浓度在0～0.8μg/25 mL范围内与吸光度(A)有良好的线性关系,该法灵敏度高、选择性和重现性好,用于红酒、啤酒和矿泉水中铁的测定,所得结果和火焰原子吸收光谱法结果相符,测得值的相对标准偏差为1.3%～3.1%,回收率为98%～101%。A new high sensitive spectrophotometric method was developed for determination trace iron. The method was based on the reaction of Fe （Ⅲ） with SCN（I） and Rhodamine B, which forms a stable blue ternary ion complex system in sulfuric acid medium in the presence of polyvinyl alcohol and gelatin. The most absorption wavelength for 620 nm, the linear regression equation is y = 0. 924× ＋ 0.281 3, the corre lation coefficient is 0. 999 4, and apparent molar absorptivity is 3.38 μ 106 L · （tool ·cm） -1 ,with de tection limit of 0.025 μg/L , the linear range was 0 ～ O. 8 μg/25 mL, this method is high sensitivity, se- lectivity and simplicity. Samples of mineral water, grape wine and beer were analyzed by this method for their Fe（ Ⅲ） contents. The results obtained were in conformity with the results found by FAAS,the rela- tive standard deviations （RSD） of determinations were 1.3 % ～ 3.1% and recoveries were 98% ～ 101% .

关 键 词：分光光度法 铁 硫氰酸根 罗丹明B 

分 类 号：O657.32[理学—分析化学]