石墨炉原子吸收法测定尿铬的实验条件探讨

目的对石墨炉原子吸收法测定尿铬的实验条件进行探讨,并确定方法最佳试验条件,以改善并提高本方法的灵敏度和准确度。方法优化石墨炉在测定尿铬的升温程序,确定最佳样品保存酸度和保存时间,应用硝酸铵基体改进剂改善背景干扰,比较并确定合适的线性范围,对实际样品进行加标回收率和精密度测定。结果对石墨炉测定尿铬的升温程序进行优化后提高了测定方法的灵敏度,确定使用1%的硝酸作为样品的保存酸度,加入10μL30%的硝酸铵基体改进剂,经比较后确定0～10μg/L铬工作曲线作为最佳线性范围。对54份尿样进行测定,样品均值加标回收率为97%~110%,精密度均值为3.57%~7.89%。结论应用石墨炉原子吸收法测定尿铬,对实验条件进行探讨后,确定样品最佳保存酸度和保存时间,通过优化石墨炉升温程序并加入硝酸铵基体改进剂,确定0～10μg/L铬线性范围后,方法更可靠,灵敏度更高,

Experiment condition exploration of urine Chromium determination by craphite furnace atomic absorption spectrometry

Objective To explore the experiment condition of urine Chromium determination by graphite furnace atomic absorption spectrometry(GFAAS),and ascertain the optimum experiment condition in order to improve and increase its sensitivity and accuracy.Methods The temperature program of urine Chromium determination was optimized by graphite furnace,and defined the best preserved acidity and storage time of samples.Ammonium nitrate as a matrix modifier was used to improve background absorption.The appropriate linear range,and measured the standard recovery rate and its accuracy of the real samples were compared and determined.Results After the optimization of temperature program for determining urine Chromium by graphite furnace,it improved its sensitivity.The preserved acidity of sample was 1% nitric acid with 10 μL 30% ammonium nitrate as its matrix modifier,and 0-10 μg/L Chromium working curve was ascertained as the best linear range after comparison.54 samples of urine were measured,the average standard recovery rate of the samples was 97%-110%,and the average accuracy was 3.57%-7.89%.Conclusion Application of GFAAS is used to measure urine Chromium,after the exploration of experiment condition,the optimum preserved acidity and time of samples are determined.It becomes more reliable and sensitive after optimization of temperature program of graphite furnace with the addition of ammonium nitrate as its matrix modifier,and the ascertained linear range with 0-10 μg/L of Chromium.