| Fluorine as a trace element essential to human has the vital significance to human growth. The shortage of fluorine will be due to osteoporosis and dental caries. Because of rich fluorine contained in the tea, it is extremely vital significance to the human body by drinking tea. But the human body is extremely sensitive to the fluorine content, once intake exceeded safety limits, it will cause acute or cumulative fluorosis. In recent years a large number of fiuorosis phenomenon caused by long-term consumption tea of high fluorine content were newly discovered. Therefore, studies on fluorine content of each kind of tea, as well as the fluorine leaching rate under different infusion way, has a vital significance for regarding guaranteed people's health.Pu'er tea is post-fermented tea, bears stores, has the characteristic of the more stored the better. Because of its mild and delicious, Pu'er tea is good for everybody, and also has variety kinds of health protection function, receives more and more people's favor. At present there are more researches on fluorine content of brick tea as well as the fluorosis phenomenon caused by long-term consumption brick tea, but the researches on Pu'er tea is very little and without system.This article selects different Pu'er tea of Yunnan Xishuangbanna, Honghe, Simao and Lincang as the experimental sample, uses the method of fluorine ion electrode selection to determine the fluorine content of Pu'er tea, researches the dynamic changes of fluorine leaching rate under different infusion way, uses the weight method to determine crude fiber content, uses colorimetry to determine aluminum element content, uses atomic absorption spectrophotometry to determine the content of iron, calcium, copper, manganese, magnesium elements, and uses DPS data processing system to analyzes the relativity between these material content. The main results are as follows:1,The fluorine content of different Pu'er tea exist remarkable difference, the highest content is 112.71mg/kg, the lowest content is 39.05mg/kg. However these content is not exceed the requirement of fluorine content in tea should less than 200mg/kg which is stipulated in agricultural profession standard NY 659-2003. The fluorine content between different producing areas' samples and different samples in the same producing areas also has remarkable difference. In the six standard samples of Pu'er tea, the difference of fluorine content is extremely remarkable, and along with the depressing of class, the fluorine content increases, the range of variation is 77.39mg/kg～95.28mg/kg.2,The fluorine content of different tea soup exist remarkable difference, along with the increase of infusion time, the fluorine content in tea soup is reduced drastically, furthermore the trend of decline gradually changes slow. The fluorine leaching rate also has the reduction, from 24.4% drops to 14.6%. Five infusion times leach fluorine 319.26μg in all; the total extraction rate is 94.4%, in the first three tea soup the fluorine leaching rate achieves 63.6%.3,Extraction temperature, time, the ratio of tea to water have remarkable infection to fluoride leaching rate in the process of infusion tea. Their primary and secondary effect order is: the ratio of tea to water>time>temperature. Follow the single factor effect analysis: When the temperature is lower, the fluorine leaching rate is positively correlated with it, about 97℃, the fluorine leaching rate reaches the maximum value, and then with the increase of temperature the fluorine leaching rate decreases slowly; when the time less than 22 min, the fluorine leaching rate increases with the increase of time, highest at about 23min, followed the contrary; the fluorine leaching rate unceasingly increases along with the ratio increase. It is remarkable interaction between the time and ratio by the analysis of regression equation, and the two factors are direct ratio to the fluorine leaching rate. When the extraction time is at 5min and the ratio of tea to water is 1:50, the fluorine leaching rate is lower in the tea.4,The crude fiber content of different tea changes bigger, ranging from 8.19%～14.50%, showed the tenderness of the samples is also widely. Using DPS data processing system to analyze the relativity between fluorine content and crude fiber content in the sample, obtained that it is extremely remarkable positive correlation between them, the correlation coefficient is 0.8966.5,The aluminum element content of different tea sample differ remarkable, the range of variation from 245.43mg/kg～991.95mg/kg, The highest content is 4 times to the lowest content. Between the aluminum element content and the fluorine content, the aluminum element content and the crude fiber content presents extremely remarkably positive correlation. Its correlation coefficient is 0.9065 and 0.8620.6,The results of the content of iron, calcium, copper, manganese, magnesium elements of Pu'er tea show that, the content of the same mineral element in different sample significantly different, the content of different mineral element in the same sample also significantly different. The content of iron, calcium elements with the fluorine content present extremely remarkably positive correlation, the content of copper, magnesium elements with the fluorine content present extremely remarkably negative correlation, the content of manganese element with the fluorine content present remarkably positive correlation. The content of iron, calcium, manganese elements with the crude fiber content present extremely remarkably positive correlation, the content of copper, magnesium elements with the crude fiber content present extremely remarkably negative correlation.7,The sensory quality of different tea sample differ obvious. The tenderness scores of tea sample with the fluorine content and with the crude fiber content both presents extremely remarkably negative correlation. That is, the higher the tea tenderness, the lower the content of fluorine and crude fiber; the lower the tea tenderness, the higher the content of fluorine and crude fiber.
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