浊点萃取-石墨炉原子吸收光谱法测定尿液中痕量铊

Determination of trace amounts of thallium in urine by turbidity point extraction-graphite furnace atomic absorption spectrometry

目的建立尿液中痕量铊的原子吸收光谱法。方法采用5-溴-2-吡啶偶氮-5-二乙氨基苯酚为螯合试剂、Triton X-100为浊点萃取剂提取铊,建立浊点萃取-石墨炉原子吸收光谱法测定尿样中铊含量;分析测定尿样时适宜的pH值、试剂浓度、温度、时间等指标。结果浊点萃取尿样中铊(Ⅲ)的最优条件为pH 9.0、75℃水浴20 min,Triton X-100的浓度为0.1%。在优化后实验条件下,建立的方法测定尿样中铊(Ⅲ)的检出限为0.028μg/L;相对标准偏差(RSD)为3.55%～4.21%(c值为0.5μg/L,n=7);加标回收率为82.7%～113.1%。结论建立的方法灵敏高,结果准确可靠,可以用于尿样痕量铊(Ⅲ)的测定。

Objective To establish an assay to determine trace amounts of thallium in urine by atomic absorption spectrometry. Methods Using 5-bromo-2-pyridylazo azo-5-diethylaminophenol as chelating reagent, Triton X-100 was used to extract thallium from urine samples, turbidity point extraction-graphite furnace atomic absorption spectrometry assay was established to determine thallium content. The pH value, reagent concentration, temperature, time and other objective parameters were optimized. Results The optimal turbidity point extraction to determine thallium in urine （Ⅲ） were under the conditions of pH 9.0, 75 ℃ water bath for 20 min and 0.1 % Triton X-100. Under which the detection limit of thallium （Ⅲ） in urine was 0.028 μg/L. The relative standard deviations （ RSDs ） were 3.55%-4.21 % （ c = 0.5 μg/L, n =7）. The recovery rates were 82.7%-113.1 %. Conclusion The established method is sensitive and the results are accurate, which can be used for the determination of trace amounts of thallium （Ⅲ） in urine samples.