广州市市售普洱茶镉元素残留现状及分布差异

Cadmium residual status in commercially available Pu'er tea and its distribution difference in Guangzhou City

目的了解广州市市售普洱茶镉元素残留现状及其分布差异。方法 2013—2015年在广州市超市、批发市场、零售店、餐饮单位、茶博会、网购六类环节采集391份普洱茶样品,使用电感耦合等离子体质谱仪,依据国家食品安全风险监测工作手册中《食品中铅、镉、砷、镍、铬、铜、汞测定的电感耦合等离子体质谱分析方法标准操作程序》进行检测。结果 391份普洱茶样品镉残留量范围为0.006～0.217 mg/kg,中位数为0.032 mg/kg,均值为（0.035 9±0.019 2）mg/kg,P90为0.054 9 mg/kg;其中检测结果≤0.05 mg/kg的占84.40%,0.05～0.10 mg/kg的占14.58%,〉0.10 mg/kg的占1.02%;普洱茶熟茶中镉残留量高于生茶,散茶镉残留量高于饼茶,砖茶镉残留量高于散茶、沱茶与饼茶,餐饮环节采集的普洱茶镉残留量高于超市、批发市场、零售店、茶博会环节,网购环节采集的普洱茶镉残留量高于零售店环节,价位低于50元/kg的样品普洱茶镉残留量高于200～300元/kg和300元/kg以上的样品;储存年限〉10 a的普洱茶样品镉残留量高于储存年限〈1 a的样品。结论普洱茶中镉残留量较低,检出值均低于NY 659-2003规定的镉限量值1 mg/kg,超过8成普洱茶样品镉残留量低于检出限;普洱茶中镉元素残留量在不同工艺、形态、场所及价位等方面存在差异。

[Objective]To know the cadmium residual status in commercially available Pu＇er tea in Guangzhou City,and learn about its distribution difference.[Methods]During 2013-2015,391 Pu＇er tea samples were collected from supermarkets,wholesale markets,retail stores,restaurants and Tea Expo in Guangzhou,as well as online stores. By using the inductively coupled plasmamass spectrometer,the detection was performed according to the Determination of lead,cadmium,arsenic,nickel,chromium,copper,mercury in food by inductively coupled plasma-mass spectrometry（ICP-MS）from the national food safety risk monitoring workbook.[Results]The cadmium residuals of 391 Pu＇er tea samples were between 0.006 mg/kg and 0.217 mg/kg with the median of 0.032 mg/kg,the mean was（0.035 9±0.019 2）mg/kg,and P90 was 0.054 9 mg/kg. The samples with results≤0.05 mg/kg,0.05-0.10 mg/kg and0.10 mg/kg accounted for 84.40%,14.58% and 1.02%,respectively. The cadmium residual of ripened tea was higher than that of raw tea,the cadmium residual of scattered tea was higher than that of cake tea,and the cadmium residual of brick tea was higher than that of scattered tea,bowl tea and cake tea. The cadmium residual of Pu＇er tea samples collected from restaurants was higher than that of Pu＇er tea samples collected from supermarkets,wholesale markets,retail stores and Tea Expo,and the cadmium residual of Pu＇er tea samples collected from online stores was higher than that of Pu＇er tea samples collected from retail stores. The cadmium residual of Pu＇er tea samples which price is lower than 50 RMB/kg was higher than that of Pu＇er tea samples which price is 200-300 RMB /kg and higher than 300 RMB /kg. The cadmium residual of Pu＇er tea samples which storage time is longer than 10 years was higher than that of Pu＇er tea samples which storage time is shorter than1 year.[Conclusion]The cadmium residual of Pu＇er tea is low,the testing results are lower than 1 mg/kg which the standard is limited by NY 659-2003,and over eighty percent of Pu＇er tea samples show the results lower than detection limit of cadmium. There are differences in cadmium residual among Pu＇er tea samples of different process,form,place and price.