食品科学 ›› 2011, Vol. 32 ›› Issue (18): 218-220.doi: 10.7506/spkx1002-6630-201118047

• 分析检测 • 上一篇    下一篇

微波消解-电感耦合等离子体发射光谱法测定茶叶中的镉

杨秀芳1,许 凌1.2,徐建峰1,2,*,涂云飞1,孔俊豪1   

  1. 1. 中华全国供销合作总社杭州茶叶研究院
    2.国家茶叶质量监督检验中心
  • 出版日期:2011-09-25 发布日期:2011-09-24
  • 基金资助:
    浙江省分析测试基金项目(03017)

Determination of Cadmium in Tea Using Microwave Digestion and Inductively Coupled Plasma Atomic Emission Spectroscopy

YANG Xiu-fang1,XU Ling1.2,XU Jian-feng1.2,*,TU Yun-fei1,KONG Jun-hao1   

  1. (1. Hangzhou Tea Research Institute, All China Federation of Supply and Marketing Cooperatives, Hangzhou 310016, China; 2. National Tea Quality Supervision and Inspection Center, Hangzhou 310016, China)
  • Online:2011-09-25 Published:2011-09-24

摘要: 采用微波消解前处理技术,结合电感耦合等离子体发射光谱法对茶叶中镉元素含量进行测定,并以该方法对随机抽取的绿茶、乌龙茶、茉莉花茶和普洱茶各10个茶样中的镉元素含量进行分析。结果表明:镉标准物质质量浓度在0~100μg/L范围内,线性良好,相关系数R为0.9998,仪器检出限为1.88μg/L;茶样添加标准物质的回收率在95.7%~102.3%之间,茶样中镉元素含量6次重复测定的相对标准偏差为1.1%,方法回收率与精密度都较好,适合茶样中镉的快速测定;随机抽取的40个茶样的镉含量在0.017~0.138mg/kg之间,平均值为0.082mg/kg±0.028mg/kg,其中被检测的绿茶镉含量为0.060mg/kg±0.014mg/kg,乌龙茶为0.098mg/kg±0.027mg/kg,茉莉花茶为0.082mg/kg±0.032mg/kg,普洱茶为0.090mg/kg±0.023mg/kg。绿茶与其余3类茶镉含量的平均值差异显著(P<0.05)。

关键词: 茶叶, 镉, 微波消解, 电感耦合等离子体发射光谱

Abstract: The contents of cadmium in tea samples including green tea, oolong tea, jasmine tea, and Pu,er tea were determined using microwave digestion followed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The linear range was from 0 to 100μg/L (R2 = 0.9998). The limit of detection (LOD) for cadmium was 1.88μg/L. The spike recovery was ranged from 95.7% to 102.3% with a relative standard derivation (RSD) of 1.1%. In conclusion, the method is a rapid, convenient, and highly sensitive method to determine cadmium content in tea samples. The contents of cadmium in randomly sampled forty tea samples were between 0.017 mg/kg and 0.138 mg/kg with an average of (0.082±0.028) mg/kg. The average content of cadmium in green tea showed a significant difference when compared with other tea samples (P<0.05).

Key words: tea, cadmium, microwave digestion, inductively coupled plasma atomic emission spectroscopy (ICP-OES)

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