摘要
基于稀HCl介质中,在表面活性剂TritonX-100存在下,痕量钒(V)对重铬酸钾氧化偶氮胂Ⅲ(AsAⅢ)的褪色反应有明显的催化作用,建立了测定痕量钒(V)的动力学光度法。方法检出限为0.15μg/L,线性范围为0～20.0μg/L。在25mL溶液中,测定0.5μg钒(V)的相对标准偏差为3.23%(n=11)。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响。研究了反应的最佳条件,并测定了一些动力学参数,催化反应的表观活化能为30.21kJ/mol。结合溶剂萃取分离,实现了样品中痕量钒(V)的测定。方法用于人发、植物、茶叶样品中钒(V)的测定,结果与认定值相符;用于测定食品中的痕量钒(V),结果与原子吸收光谱法相符。相对标准偏差为1.18%～4.00%,标准加入回收率为97.5%～102.5%。
A new kinetic spectrophotometric method for the determination of trace vanadium（V） has been developed; the method is based on the catalytic effect of trace vanadium（V） on oxidation of arsenanzo Ⅲ （AsA Ⅲ ） with bichromate in dilute HCI solution. The detection limit is 0.15μg/L and the linear range of determination is 0.0-20.0μg/L. The relative standard deviation for the determination of vanadium（V） at the concentration of 0.5μg/ 25mL is calculated to be 3.23%（n=11）. The factors such as acidity, concentrations of reactants, reactive time, temperature, influence of coexisting ions on the reaction and the optimum reaction conditions of the reaction and some kinetic parameters are determined; the apparent activation energy of the reaction is 30.21kJ/mol. Combined with solvent extraction separation, the method has been applied to the determination of vanadimol（V） in human hair, plant and tea samples, the results are in agreement with certified values; the method has also been applied to the determination of trace vanadium（V） in foodstuff samples with the relative standard deviation of 1.18%-4.00% and the recovery of 97.5%-102.5%, the results are in good agreement with those provided by AAS method.
出处
《食品科技》
CAS
北大核心
2007年第1期174-178,共5页
Food Science and Technology
基金
江西省自然科学基金项目(0520002)。
