部分市售茶叶中铅、铬污染状况调查

Investigation of lead and chromium in tea from some markets in China

目的了解市售茶叶中铅、铬两种重金属元素的污染状况,调查茶叶中铅、铬的本底值,为食品安全风险评估提供数据支持。方法从7个省、直辖市和自治区采集了420份茶叶样品,样品包含人们日常消费的主要茶叶品种,采用GB 5009-12-2010和GB 5009-123-2003中石墨炉原子吸收分光光度法对样品中的铅、铬两种元素的含量进行测定,依据GB 2762-2012茶叶中铅的限量和NY 659-2003中铬的限量对结果进行判定。结果茶叶中铅的检出率为90.7%,超标率为0.48%,铬的检出率为93.1%,超标率为0.71%,合格率略高或持平于2005~2009年监测结果。不同产地、不同品种、不同包装形式的茶叶之间铅铬含量存在差异。结论市售茶叶中铅、铬两种重金属元素的总体污染较低,但个别样品存在铅、铬含量超标现象,应引起适当的关注。

Objective To understand the contamination status and investigate the background value of lead and chromium in tea, providing the data support for food safety risk monitoring. Methods The 420 tea samples were collected from 7 provinces of China, including the main varieties which are regularly consumed by people. The contents of lead and chromium in these tea samples were determined by graphite furnace atomic absorption spectrometry (GFAAS) with GB 5009-12-2010 and GB 5009-123-2003. The results were evaluated by comparison to the limit for lead and chromium regulated by China Food Safety Standard GB 2762-2012 and NY 659-2003. Results The detection rate of lead is 90.7%, of which 0.48%of the total exceeded the residue limit of 5 mg/kg regulated in GB 2762-2012, and the detection rate of chromium is 93.1% with the violation rate of 0.71%. The contamination levels were comparable or a little bit higher to the monitoring results acquired from 2005 to 2009. There were some difference of lead and chromium content in the aspects of place of production, the variety and the style of package. Conclusion The results indicated that the residue levels of lead and chromium in tea was acceptable, however, there were still few samples did not comply with the residue limits according to GB 2762-2012 in the aspect of lead and chromium, which should be paid more attention.