液相色谱-电感耦合等离子体质谱法检测茶叶中“美术绿”的含量

Determination of lead chrome green in tea by liquid chromatography-inductively coupled plasma mass spectrometry

中文关键词:  美术绿  茶叶  液相色谱-电感耦合等离子体质谱法

英文关键词:lead chrome green  tea  liquid chromatography-inductively coupled plasma mass spectrometry

中文摘要:

      目的 建立液相色谱-电感耦合等离子体质谱法检测茶叶中“美术绿”的含量。方法 茶叶样品经电炉灼烧后用0.25 mol/L NaOH和0.14 mol/L Na2CO3的混合碱性提取液95 ℃搅拌提取灰分10 min。经Agilent G3268型阴离子色谱柱分离, 以50 mmol/L硝酸铵缓冲盐为流动相等度洗脱。在上机测定前调pH值至与流动相接近, 采集52Cr为目标物, 以质谱测定。结果 该方法在5~500 μg/L范围内线性良好, 相关系数为0.9996, 3个添加水平下的回收率在82.1%～100.9%, 相对标准偏差小于10%, 检出限为10 mg/kg。结论 该方法测定染色茶叶中的“美术绿”, 准确高效, 适用性强, 可满足市场监管的需要。

英文摘要:

      Objective To establish a method for determination of lead chrome green in tea by liquid chromatography-inductively coupled plasma mass spectrometry. Methods After the sample was burned in an electric furnace, the ash was stirring extracted with a mixed alkaline extract of 0.25 mol/L NaOH and 0.14 mol/L Na2CO3 at 95 ℃ for 10 min. The samples were separated with Agilent G3268 anion column by isocratic elution using 50 mmol/L ammonium nitrate buffer salt. The pH value was adjusted to be close to the mobile phase before the measurement on the computer. The 52Cr was collected as the target object and then determined by mass spectrometry. Results The method had a good linearity in the range of 5-500 μg/L, and the correlation coefficient was 0.9996. The recoveries were 82.1%-100.9%, the relative standard deviation was less than 10%, and the detection limit was 10 mg/kg. Conclusion The method for determining lead chrome green in dyed tea leaves is accurate, efficient and applicable, and can meet the needs of market supervision.