油类样品中常见金属元素的含量测定及评价

Determination and evaluation of metals in oil samples

采用H2O2-HNO3混合消解法,对7种食用油、7种餐余废弃油样品进行了前处理,采用原子吸收法对油样中的Ca、Mg、Fe、Cu、Zn、Mn、Pb、Cr等金属元素的含量进行了测定。测定结果显示,所有的油样中,均含有Ca、Mg、Zn、Cu、Fe、Mn元素,食用油中未检出Pb、Cr,但在部分废弃油样品中有检出。通过对2类油样品中金属含量的对比,发现废弃油中的8种金属含量均有增加。实验数据表明:金属元素含量增大的原因除了浓缩作用外,主要与所接触的器物有关。

In this test,the oil samples,seven edible oil and seven cooking waste oil,were pretreated by digestion of HNO_3 mixed with H_2O_2. The contents of metals,such as Ca、Mg、Fe、Cu、Zn、Mn、Pb、Cr,were determined by atomic absorption spectrometry. Results show that Ca、Mg、Fe、Cu、Zn、Mn were found in all samples. Pb、Cr were not determined in edible oil,but could be found in some cooking waste oil. Compared the metals in edibel oil and cooking waste oil,the contents of eight metals in waste oil were higher than those in edible oil. The reasons of element contents increase are mainly related to the object oil contacted,in addition to oil enrichment.