湿法消解-石墨炉原子吸收光谱法测定茶叶中铅方法的优化

Optimization of the method for determination of lead in tea by wet digestion-graphite furnace atomic absorption spectrometry

中文关键词:  湿法消解  基体改进剂  石墨炉原子吸收光谱法  茶叶  铅

英文关键词:wet digestion  matrix modifier  graphite furnace atomic absorption spectrometry  tea  lead

中文摘要:

      目的 优化湿法消解-石墨炉原子吸收光谱法测定茶叶中铅的分析方法。方法 本研究根据国标GB 5009.12-2017《食品安全国家标准 食品中铅的测定》, 对茶叶的湿法消解方法进行了方法优化。在单因素实验的基础上, 采用响应曲面法优化。结果 确定了原子吸收光谱仪的最佳测定条件为: 胶体钯的进样量为 6 μL、灰化温度为1067 ℃、原子化温度为1900 ℃。在构建的湿法消解方法和优化的原子吸收光谱仪条件下, 茶叶加标平均回收率为96.32%, 相对标准偏差为1.46%, 检出限为1.525 μg/L; 通过国家标准物质GBW10016、GBW10052、GBW10015验证方法的可行性, 检测结果与规定值符合良好。结论 该方法测定结果具有较高的精密度和准确度, 可用于茶叶中铅含量的测定。

英文摘要:

      Objective To optimize the method for determination of lead in tea by graphite furnace atomic absorption spectrometry. Methods Based on GB 5009.12-2017 National food safety standard-Determination of lead in foods, the method of wet digestion for determination of tea was optimized by response surface methodology on the basis of single factor experiment. Results The optimal determination conditions were found by response surface methodology as follows: Colloidal palladium load was 6 μL, ashing temperature was 1067 ℃, and atomizing temperature was 1900 ℃. Under the above conditions, the average recovery of lead in tea was 96.32% with a relative standard deviation of 1.46%, and the limit of detection was 1.525 μg/L. The feasibility of the method was verified by national standard materials GBW10016, GBW10052 and GBW10015, the test results were in good agreement with the specified values. Conclusion The results of this method have high precision and accuracy, which can be used for the determination of lead in tea.