铁(Ⅲ)-硫氰酸根-乙基罗丹明B缔合体系微乳液分光光度法测定铝合金中铁  

Micro-emulsion Spectrophotometric Determination of Iron in Aluminum Alloy by the Associated System of Fe(Ⅲ)-Thiocyanate-Ethyl Rhodamine B

作　　者：董文丽[1] 徐刚[1] 

机构地区：[1]重庆科技学院化学化工学院,重庆401331

出　　处：《理化检验（化学分册）》2013年第1期75-77,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：提出了微乳液分光光度法测定铝合金中铁含量的方法。在比色管中,先后加入0.5 mol·L^(-1)硫酸溶液3.00 mL、铁(Ⅲ)标准溶液,2 mol·L^(-1)硫氰酸钾溶液3.00 mL、5 g·L^(-1)阿拉伯树胶溶液0.8 mL、微乳液0.70 mL及1×10^(-3) mol·L^(-1)乙基罗丹明B溶液3.00 mL使反应生成铁与硫氰酸盐的络阴离子和乙基罗丹明B的缔合物。微乳液和阿拉伯树胶对此显色体系具有显著的增溶作用。铁(Ⅲ)的质量浓度在0.026～0.36 mg·L^(-1)范围内与其吸光度呈线性关系。反应体系的吸收峰位于波长620 nm处,在此波长条件下测定其表观摩尔吸光率为1.08×10~5 L·mol^(-1)·cm^(-1)。方法用于测定铝合金试样中铁量,测定值的相对标准偏差(n=5)小于2%。A micro emulsion spectrophotometric method for determination of iron in aluminum alloy was proposed. Fe （III） was reacted with 3.00 mL of 2 mol · L^-1 KSCN solution and 3.00 mL of 1.0× 10^-3mol · L^-1 ethyl rhodamine B in 0. 5 mol · L^- 1 He SO4 solution in the presence of 0.8 mL of 5 g ·L ^-1 gum arabic and 0.70 mL of micro-emulsion solution. An association complex was formed between the anionic complex of [Fe（CN）6 ]^3- and the cation of ethyl rhodamine B （ERB＋ ）, which was solubilized by solutions of gum arabic and micro emulsion. Linear relationship between values of absorbance and mass concentration of Fe （ III ） was found in the range of 0. 026-0.36 mg · L^- 1. Apparent molar absorptivity of the associated system found was 1.08 × 10^5L · mol^-1 · cm ^-1 at the wavelength of its absorption maximum 620 nm. The proposed method was applied to the determination of Fe in samples of aluminum alloy, giving values of RSD＇s （n=5） less than 2%.

关 键 词：微乳液 分光光度法 铁 硫氰酸盐 乙基罗丹明B 铝合金 

分 类 号：O657.32[理学—分析化学]