微波消解样品-电感耦合等离子体原子发射光谱法测定植物中9种必需元素

ICP-AES Determination of 9 Essential Elements in Plants with Microwave Assisted Sample Digestion

植物样品置于聚四氟乙烯罐中，加入硝酸及过氧化氢后在MARS 5微波消解仪中按设定程序加热消解。样品溶液经定容为一定体积并保持一致的稀硝酸酸度，直接进样进行电感耦合等离子体原子发射光谱法（ICP-AES）分析，在选定的优化分析条件下同时测定其9种元素（钾、钙、镁、磷、硼、锌、铜、铁及锰）的含量。包括样品消解在内，分析全过程只需3-4 h。用标准曲线法进行定量，所得各元素的标准曲线均有良好的线性关系。应用此方法分析了一种茶叶标准物质（GBW 07605），所得9种元素的测定结果与证书值相符，各元素测定值的相对标准偏差（n=5）在0.3%-4.7%之间。

Plant sample was digested with HNO3 and H2O2 in a PTFE vessel and heated in the MARS 5 Microwave Digester under a prescribed working program. The sample solution in a definite volume of dil. HNO3 acid was used directly for the ICP-AES determination of 9 essential elements （K, Ca, Mg, P, B, Zn, Cu, Fe, Mn） under the optimized conditions. Only 3-4 hrs. were required for the whole process of analysis, including sample digestion. Method of standard curve was used in the determination. Good linearity was obtained for the standard curves. The proposed method was used to analyze a CRM of tea （GBW 07605）, giving results in consistency with the certified values and values of RSD＇s （n=5） in the range of 0. 3%--4. 7%.