酰基吡唑啉酮螯合剂测定矿泉水中痕量铅的分光光度法研究

摘要

本论文在室温下,以1-对氯苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5为螯合剂,应用分光光度法测定市售矿泉水中痕量铅离子的含量,本螯合剂在570 nm处有最大吸收波长.显色时间为35min.实验对九种常见阳离子进行干扰考察,发现在测定允许范围内有六种离子对测定结果存在较大干扰,加入硫脲和柠檬酸三铵作为掩蔽剂,可以消除干扰离子的干扰,本实验表明该螯合剂用于分光光度法测定含铅物质中的铅含量的操作简单,时间短,不需要萃取分离,试剂用量少,加标回收率高,相对标准偏差小,准确度和灵敏度较高.此方法也可以用于其他样品中的铅离子测定.%Spectrophotometric method was established for the determination of lead content in mineral water by synthesizing a novel a acylpyrazolone ligands,1 -(p-chlorophenyl)-3 -methyl-4 -benzoyl-5 -pyrazolone as chelating agent,Xylenol orange as chromogenic agent,ammonium citrate and thiourea as masking agent. In the acetic acid-sodium acetate buffer solution at pH value 5. 5,lead ion and chromogenic agent to form a red complex,at 570 nm has a maximum absorption wavelength. At room temperature,color time for 40min. Experiment in the range of determination,there are six kinds of ions on the determination results have great influence,using thiourea and citric acid ammonium as a masking agent,can eliminate the interference of these ions. The experimental results show that the determination of lead content in mineral water by spectrophotometry has great advantages of simple operation,time saving,less reagent consumption,high precision and sensitivity. This method can also be used for the determination of lead ion content in other samples.