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.