Multielement analysis of Chinese tea (Camellia sinensis) by total-reflection X-ray fluorescence

Total-reflection X-ray fluorescence (TXRF) was used for the simultaneous determination of 15 elements in tea samples which were produced either by acid digestion or acidified infusion of tea leaves (Camellia sinensis). The accuracy and precision of the method were checked by its application to a certified reference material (GBW 08505:tea). A variety of 39 tea samples of different kinds andior qualities produced in different regions of China were analysed. The range and mean of the concentrations of elements in the tea leaves (0.1-30.000 mu g g(-1)) and their solubility in infusions (0.5-85%) were determined and the influence of the origin, type and quality of the tea samples was studied. In some tea leaves produced in a Se-rich region, the content of Se was found to be very high (up to 7.5 mu g g(-1)), in contrast to a concentration of only about 0.1 mu g g(-1) Se in most of the tea leaves examined.