Analysis of trace element contents in teas from Fujian Province

Objective To investigate the contents of trace elements,including iron,manganese,copper,zinc,cobalt,selenium,chromium and nickel in different varieties of teas collected from different areas in Fujian Province so as to provide scientific evidence for tea cultivation,tea nutrition and hygiene. Methods The contents of the trace elements in 135 tea samples randomly collected from Fujian Province were determined by inductively coupled plasma mass spectrometry with microwave digestion.Results The ranks of the contents of the 8 trace elements in different kinds of tea samples were all Mn Fe Zn Cu Ni Cr Co≈Se,although the contents of the same trace elements were varied among them. The highest contents of the trace elements were shown as follows: Mn in Tie- guanyin tea; Fe,Zn,Cu and Cr in Gong- fu black tea; Ni in White Peony; Co in Yong-chun finger citron tea and Se in Lapsang Souchong. The average contents of Fe,Zn,Cu and Ni in the teas from northern Fujian were significantly higher than those from southern Fujian( P 0. 01),while the average content of Mn was lower( P 0. 01). No statistically significant difference was found between the average contents of the other elements in the two regions( P 0. 05).Conclusions Multiple trace elements are rich in the teas from Fujian Province,and their contents are varied in teas of various categories and from different regions.