D市售茶叶浸出液中重金属含量与食用风险分析_食品科学与工程.rar

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  • 更新时间:2016-08-11
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摘要:本课题对徐州市售茶叶的浸出液中重金属铅、镉、铜、锰进行了细致的研究。根据浸泡时间、浸泡次数和浸泡水温三种条件的选择不同进行区分,并采用微波消解的方法对原料进行预处理,最后用石墨炉原子吸收分光光度计测量,得到徐州市售茶叶浸出液中各种重金属含量,先进行横向比较确定出污染较重的茶叶品种,并通过对其产地和制作工艺的研究找出污染的原因;再进行纵向比较确定出最合适的泡茶时间、泡茶水温和泡茶次数,并由此制定出科学有效的饮茶方案。

   实验表明,根据实验数据显示,在横向的比较中,绿茶中的龙井和碧螺春的铅污染比较严重,红茶中的正山小种的镉污染比较严重,龙井、正山小种和乌龙茶中的铜含量较高,所有茶中的锰含量差距不大。在纵向的比较中,在相同的条件下,浸泡时间越长,浸出的重金属越多;水温对重金属的浸出影响不大;第一遍浸出的重金属较多,第二次和第三次浸出的重金属相差不多。

关键词 茶叶;微波消解;重金属;原子吸收

 

Abstract:The subject of tea water in xuzhou market of heavy metal lead, cadmium, copper, manganese pollution detailed study. The experiment will study from the three conditions of soaking time, soaking times and temperature of the tea water.and finally choose microwave digestion to sample processing, with graphite furnace atomic absorption spectrophotometer measurement, get xuzhou tea water for heavy metal content.First to compare to determine the varieties of tea heavy pollution, through the study of the place of origin and the production process to find out the reason of pollution.Then to compare to determine the most appropriate tea time, temperature and the times of soaking. And thus make the scientific and effective plan of drinking.

    The experimental results show that when compared with the varieties of tea heavy pollution, lead pollution in Longjing and biluochun of green tea is serious.Cadmium pollution in Lapsang souchong of black tea is serious.copper pollution in Longjing,Lapsang souchong and oolong tea of black tea is serious. the manganese content in all the tea is similar.In the same conditions, the longer soaking time, the more heavy metal leaching.The temperature has little effect on heavy metal leaching. The first heavy metal leaching is serious.The second times and third times have the same heavy metal content.

Keywords  tea  microwave digestion  heavy metal  atomic absorption

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