尿中砷的原子荧光光谱测定法样品前处理及标准的研究

Determination of arsenic in urine by atomic fluorescence spectrometry: a research on sample pretreatment and standard

目的对尿中砷的原子荧光光谱测定法进行样品不同前处理方法的比较以及标准曲线和工作曲线的比较。简化分析程序,使得该法更易推广普及。方法配制两套相同浓度的砷标准系列进行消化与不消化的比较,将两组数据进行统计处理,比较有无显著性差异;尿样采用硝酸高氯酸在自控电热器上消解,用加标回收率评价此消化方法测定的准确度。高、低两个浓度的样品各取6份消化测定,计算精密度,看其消化过程中的稳定性。结果尿砷标准系列消化与不消化没有显著性差异,尿样采用硝酸高氯酸在自控电热消化器上消化,高、低浓度的加标回收率分别为99.8%、104.3%。高、低浓度的样品精密度分别为6.3%、9.5%。结论该法的改进不影响方法的灵敏、准确和稳定性,且大大简化了操作程序,便于操作,减轻了分析人员的工作量,也减少了复杂程序可能带来的误差,使用更少的仪器设备,更利于推广、普及。

[ Objective ] To compare the different sample pretreatment methods of atomic fluorescence spectrometry for detecting the arsenic in urine, and compare the standard curve and the working curve, simplify the analysis procedure, so as to promote the popularization of this method. [ Methods] Two sets of arsenic standard series with same concentration was respectively digested and not, and the data were analyzed statistically and compared. Urine samples were digested with nitric acid and perchloric acid in automatic control electric heater. The recovery of standard addition was applied on evaluating the accuracy of this digestion method. Six sampies were collected from each of upper and lower concentration groups, the precision was calculated, and the stability in digestion process was estimated. [ Results] There was no significant difference between digested treatment and non-digested treatment of urine arsenic standard series. By digesting the urine samples with nitric acid and perchloric acid in automatic control electric heater, the recovery of standard addition of upper and lower concentration groups was 99.8% and 104.3% respectively. The precision of upper and lower concentration groups was 6.3% and 9.5% respectively. [ Conclusion] The improvement will not affect the accuracy, pre- cision and stability of this method, and can greatly simplify the analysis procedure, get easy operation, alleviate the workload of an- alysts, reduce the errors which are caused by the complex program, and use less apparatus, so as to promote the popularization.