锡(Ⅳ)-磺基水杨酸-溴邻苯三酚红-溴化十六烷基rn三甲基 铵胶束混配络合物的显色反应

摘要

在pH 1.6的氯乙酸缓冲介质中，溴化十六烷基三甲基铵存在下，Sn(Ⅳ)与溴邻苯三酚红及磺 基水杨酸形成(1+2+1)的胶束混配络合物。络合物的最大吸收波长为540nm，表观摩尔吸光系 数为8.9×104L*mol-1*cm-1。Sn(Ⅳ)浓度在0—0.6mg/L范围内符合比耳定律。方法的选择性及稳定性都比无磺基水杨酸时好，适用于罐头盒中微量锡的测定，结果令 人满意。%In the presence of pH=1.6 chloroacetic acid buffer solution and cetyltrimethylam monium bromide medium,tin(Ⅳ) forms a micellar mixed ligand complex with bromopy rogallol red(BPR) and sulfosalicylic acid(SSal).The composition of tin(Ⅳ)，BPR and SSal micellar mixed ligand complex was determined to be 1∶2∶1.The maximum absorption of the complex is at 540nm and the apparent molar absorptivity is 8. 9×104 L*mol-1*cm-1.Beer's law is obeyed in the range of 0—0.6 mg/L for tin(Ⅳ).The selectivity and stability of this method is higher than that of in the absence of sulfosalicylic acid.The method has been applied to determ ine trace tin(Ⅳ) in tinned food with satisfactory results.