原子荧光光谱法测定茶叶中的硒含量

Determination of Selenium in Tea by Atomic Fluorescence Spectrometry

为了建立微波消解-原子荧光光谱法准确快速测定茶叶中硒含量的方法。样品经微波消解后,分别从是否添加铁氰化钾,添加的比例及添加后反应的时间三方面进行考察,确定添加铁氰化钾、试样-铁氰化钾(4∶1,v/v)、添加后反应30min为实验最佳优化方法。结果表明,硒质量浓度在0~100ng/mL范围内呈较好线性关系,相关系数R2为0.9997,检出限为0.0116 mg/kg,精密度RSD值为0.702%~1.888%,0.015、0.020、0.200 mg/kg三个添加水平下的回收率在86.10%~94.74%之间。该方法简单易操作,灵敏度高、重复性好且稳定,结果准确,适用于茶叶中硒含量的准确快速测定。

To establish an accurate and rapid method for the determination of selenium content in tea by microwave digestion-atomic fluorescence spectrometry(AFS).After the sample was digested by microwave,it was investigated from whether potassium ferricyanide was added,the ratio of addition and the reaction time after addition.It was sure addition of potassium ferricyanide,sample-potassium ferricyanide(4∶1,v/v)and reaction for 30 min after addition were the best optimization methods for the experiment.The mass concentration of selenium showed a good linear relationship in the range of 0~100 ng/mL,the correlation coefficient R2 was 0.9997,the detection limit was 0.0116 mg/kg,and the precision RSD was 0.702%~1.888%,The recoveries at the three addition levels of 0.015,0.020 and 0.200 mg/kg were between 86.10%~94.74%.The method is simple and easy to operate,with high sensitivity,good repeatability and stability,and accurate results.It is suitable for the accurate and rapid determination of selenium content in tea.