ICP-AES用于茶油中多种无机元素的测定研究

Determination of Inorganic Elements in Oleum Camelliae by ICP-AES

采用电感耦合等离子发射光谱法(ICP-AES)对毛茶油以及精炼工艺各阶段茶油中的Ca,K,Mg,Cu,Cr,Zn,Sr等18种无机元素进行了分析测定。该方法的加标回收率为82.7%～112.5%,相对标准偏差0.00%～6.66%,18种元素的方法检测限在0.4～10μg.L-1之间。结果表明:茶油中富含多种人体所必需的无机元素。随着精炼程度的增加,多数元素含量呈下降趋势。经过脱胶后茶油中的P,Ca,Mg含量显著下降;经过脱酸和脱色工艺后,能促进油脂自动氧化的Fe,Cu,Mn,Ni等金属元素的含量明显减少;Pb经过脱胶、脱酸工艺后未检出;Co和Cd无论是在毛茶油还是精炼茶油中均未检出。经过精炼的茶油能有效地去除过量的金属元素,含量能够达到国家卫生限量标准。同时实验表明采用ICP-AES法测定茶油中的多种无机元素具有简单、快速、准确度高等特点。

In the present study, the contents of eighteen inorganic elements such as Ca, K, Mg, Cu, Cr, Zn and Sr in oleum camelliae during different stages of refining process were determined using ICP-AES technique. The recoveries obtained by the standard addition method ranged between 82.7% and 112. 5%, and RSDs were lower than 6.66%. The detection limits of the method for the eighteen elements were in the range of 0. 4-10μg . L^-1. The experimental results proved that oleum camelliae is rich in inorganic elements. The results also showed that depending on the intensity of refining, the contents of elements will decrease accordingly. After the degumming process, the contents of elements P, Ca and Mg in oleum camelliae declined remarkably. Besides, the contents of some trace elements such as Fe, Cu, Mn and Ni that cause oxidation to occur decreased significantly after refining. In addition, Pb was not detected after the degumming and deacidification process while Co and Cd were not detected both in the crude oil and the refined oil. In conclusion, through refining many excessive metal elements in oleum eamelliae were removed effectively and the levels of these elements were able to meet the national standards set by the government. Meanwhile, the experimental results indicated that the ICP-AES technique, which can be used to determine the inorganic elements in oleum camelliae, is easy to operate, rapid, accurate, and highly sensitive, and can also determine many elements simultaneously.