离子液体微萃取-石墨炉原子吸收光谱法测定尿中痕量铅

目的 建立离子液体微萃取-石墨炉原子吸收光谱法测定尿中痕量铅的方法。方法 用吡咯烷二硫代甲酸铵(APDC)为螯合剂、无水乙醇为分散剂、离子液体1-己基-3-甲基-咪唑六氟磷酸盐([Hmim][PF6])为萃取剂萃取尿中铅,在pH 9和30℃恒温水浴条件下萃取富集,离心后弃上清,以10%硝酸反萃取。离心后,取上清液加入维生素C溶液基体改进剂,混匀后测定。结果〓在0.45~75.0μg/L范围内,相关系数大于0.999,方法检出限(s/n=3)为0.45μg/L,加标回收率为94.20%~106.0%,相对标准偏差为1.35%~3.24%(n=6)。结论 本法操作简便,灵敏度高,适用于正常人群与职业接触人群尿样中铅的测定。

Determination of trace urinary lead by ionic liquid micro extraction-graphite furnace atomic absorption spectrometry

Objective To establish a method for the determination of urinary lead using ionic liquid micro extraction coupled with graphite furnace atomic absorption spectrometry. Methods Ammonium pyrrolidine dithiocarbamate (APDC) and anhydrous ethanol were used as chelating agent and dispersant,respectively.Ionic liquid 1-hexyl-3-methyl-imidazolium hexafluorophosphate [Hmim] [PF6] was used as extracting agent for the extraction of urinary lead.The urinary lead was extracted on the conditions of pH 9 and constant temperature water bath at 30℃,and the supernatant was removed after centrifugation,then 10%nitric acid was used to back-extract lead.Finally,the nitric acid solution was taken and added vitamin C solution as matrix modifier for the determination. Results In the range of 0.45-75.00μg/L,the correlation coefficient was greater than 0.999 and the detection limit (s/n=3) of the method was 0.45μg/L.The recovery rates were 94.20%-106.0 %(n=60).The relative standard deviations were 1.35%-3.24%. Conclusion The method is simple and sensitive,and it is suitable for the determination of urinary lead of normal and occupational exposure population.