石墨炉原子吸收光谱法测定尿中镉基体改进剂的优化选择

Optimal selection of matrix modifiers in determination of urinary cadmium by graphite furnace atomic absorption spectrometry

目的找出合适的基体改进剂,改善石墨炉原子吸收光谱法测定尿中镉的结果。方法分别以10 g/L磷酸氢二铵、20 g/L磷酸二氢铵和2 g/L的氯化钯作为基体改进剂,对尿样稀释5倍后,直接用石墨炉原子吸收光谱法测定尿中镉的含量。结果以2 g/L的氯化钯作为基体改进剂,方法的灵敏度、消除背景能力、检出限、精密度和回收率均优于其他2种基体改进剂,测定效果最好。结论利用2 g/L的氯化钯作为基体改进剂直接测定尿中镉可以有效消除背景干扰,是一种准确测定尿中镉的方法。

[Objective]To find out suitable matrix modifier,improve the effect of graphite furnace atomic absorption spectrometry for determination of urinary cadmium.[Methods]10 g/L diammonium phosphate,20 g/L diammonium phosphate and 2 g/L palladium chloride was respectively used as the matrix modifier for determination,the urinary samples were diluted five times,and the concentration of cadmium in urine was tested by graphite furnace atomic absorption spectrometry.[Results]The sensitivity,capaCity of eliminating background,detection limit,precision and recovery rate of 2 g/L palladium chloride were better than other two matrix modifiers,and its effect was the best.[Conclusion]2 g/L palladium chloride as the matrix modifier in determination of urinary cadmium can effectively eliminate the background interference,which is an accurate method for determination of urinary cadmium.