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

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.