钯基体改进剂-石墨炉原子吸收光谱法测定茶叶中的铅和镉

Determination of lead and cadmium in tea by graphite furnace atomic absorption spectrometry with palladium matrix modifier

中文关键词:  茶叶  铅  镉  基体改进剂  石墨炉原子吸收光谱法

英文关键词:tea  lead  cadmium  matrix modifier  graphite furnace atomic absorption spectrometry

中文摘要:

      目的 建立石墨炉原子吸收光谱法测定茶叶中的痕量铅和镉。方法 采用湿法消解对茶叶样品进行消解, 加入氯化钯、硝酸镁、磷酸二氢铵作为基体改进剂扣除样品中背景干扰的影响, 并优化仪器条件进行石墨炉原子光谱法测定。结果 测定茶叶样品中铅的最佳基体改进剂为氯化钯-硝酸镁, 测定镉的最佳基体改进剂为磷酸二氢铵+硝酸镁。铅优化后的条件为: 灰化温度为900 ℃、原子化温度2000 ℃, 镉优化后的条件为: 灰化温度为700 ℃, 原子化温度1100 ℃。结论 本方法简便、快速、准确, 可适用于茶叶样品中铅、镉的分析。

英文摘要:

      Objective To establish a method for determination of lead and cadmium in tea by graphite furnace atomic absorption spectrometry. Methods Tea samples were wet digested by adding palladium chloride, magnesium nitrate, and ammonium dihydrogen phosphate as matrix modifier to deduct the influence of background interference in the sample. Instrument conditions of graphite furnace atomic spectrometry were optimized for determination. Results The optimal matrix modifiers for determination of lead in tea samples were palladium chloride and magnesium nitrate, and for determination of cadmium in tea samples were ammonium dihydrogen phosphate and magnesium nitrate. The optimal instrument conditions for lead were: the ashing temperature was 900 ℃ and atomization temperature was 2000 ℃. The optimal instrument conditions for cadmium were: the ashing temperature was 700 ℃ and the atomization temperature was 1100 ℃. Conclusion The developed method is simple, rapid and accurate, which can be used for determination of lead and cadmium in tea.