氢化物发生-原子荧光光谱法测定茶叶总硒时样品前处理方法的比较

On Methods of Sample Pretreatment in HG-AFS Determination of Total Selenium in Tea Leaves

摘要: 在氢化物发生-原子荧光光谱法测定茶叶中总硒量时,比较了常规湿法消解(方法1)和微波消解(方法2)两种样品前处理方法。结果表明:从测定精密度而论,方法1略优于方法2,茶叶标准样品(GBW 10016)中硒的测定值的相对标准偏差(n=8)值,方法1为0.35%,方法2为0.52%;从准确度方面,所测得方法1的回收率为94%,方法2的回收率为92%。总体上看,方法1优于方法2,更适合用于氢化物发生-原子荧光光谱法测定茶叶中总硒量。

Abstract: The sample pre-treatment of tea by the method of conventional wet-digestion (method 1) and the method of microwave assisted digestion (method 2) were compared in the HG-AFS determination of total selenium. Value of RSD (n=8) found by method 1 was 0.35%, while by method 2 was 0.52%. Value of recovery found by method 1 was 94%, while by method 2 was 92%. As revealed by the experimental results, better precision and recovery were shown by method 1 than by method 2. On the whole, pretreatment of sample by the conventional wet-digestion was preferred to be used in the HG-AFS analysis.