摘要
以从紫薯中提取的天然花青素为指示剂,指示铅(Ⅱ)的催化反应。在硫酸溶液存在的条件下,铅(Ⅱ)对高碘酸钾氧化天然花青素具有显著的催化效果,据此建立了铅(Ⅱ)的测定催化动力学新体系,讨论了催化褪色反应最佳测定条件和动力学参数:在最佳测定波长530 nm条件下,铅(Ⅱ)的质量浓度在0.01~0.26μg/mL范围内;与非催化反应体系溶液和催化反应体系溶液的吸光度差值符合比尔定律;方法的检出限为1.15×10^(-9) g/mL。动力学试验表明,该催化反应为准零级反应,活化能为38.32 kJ/mol,反应速率常数为4.22×10^(-4) s^(-1)。试验同时考察了20余种共存离子的影响。运用该法测定钢丝绳厂废水中的铅(Ⅱ),加标回收率为97.4%~102.9%,8次测定的相对标准偏差小于3.6%,本法测得值与原子吸收光谱法测得的结果一致。
The natural anthocyanins,extracted from purple sweet potato,were used as indicator for the determination of lead(II).Lead can sensitively catalyze the discoloration reaction of natural anthocyanins and potassium periodate in H2SO4 medium.The optimum kinetic conditions of the inhibited reaction have been investigated.The wavelength for the determination is 530 nm.The linear range for the determination of lead is 0.01~0.26μg/mL with the detection limit of 1.15×10-9 g/mL.The results from the studies suggested that the catalytic reaction was zero-order and the apparent activation energy of the catalytic system was 38.32 kJ/mol,and the apparent rate constant was 4.22×10-4 s-1.The interferences of twenty kinds of foreign ions were also studied.The procedure has been used to determine the lead in the wastewater from wire rope plant,with the relative standard deviation below 3.6%(n=8)and the average recovery of 97.4%~102.9%.The results obtained by this method were consistent with the results found by atomic absorption spectrophotometry.
作者
严进
顾飞琪
王从兵
YAN Jin;GU Fei-qi;WANG Cong-bing(School of Chemical and Biological Engineering,Nantong Vocational University,Nantong 226007,China)
出处
《南通职业大学学报》
2018年第1期91-95,共5页
Journal of Nantong Vocational University
基金
江苏省大学生创新训练计划项目(201711052002Y)
关键词
催化动力学光度法
铅(II)
天然花青素
高碘酸钾
钢丝绳厂废水
catalytic kinetic spectrophotometry
lead(II)
natural anthocyanins
potassium periodate
wastewater from wire rope plant
