[FAAS determination of trace elements in tea-leaves using suspension sampling with ultrasonic agitation]

It is known that some minerals and trace elements such as Cu, Fe, Zn and Mn are the necessary elements in human body. The lack of these elements can cause various diseases. Because tea contains all kinds of minerals and trace elements, drinking tea is healthy for people. In order to contrast teas of different sort grades and producing areas the minerals and trace elements in the tea have been determined using suspension sample introduction technique. To determine the content of trace elements in tea-leaves, samples were powdered and sieved after being heated at (80 +/- 2) degerees C for 4 hours. 5 mL 0.15% agar solution was added and mixed thoroughly with the samples by ultrasonic agitation. Then the prepared suspension of sample was directly introduced to FAAS for determination. The results of this method are consistent with those obtained by wet treatment method, and the relative deviation of treatment method is less than +/- 0.96%. The t-test shows that no difference was found. The present method is convenient, rapid and accurate.