植物油酸值、过氧化值的测定方法研究

Determination method of acid value and peroxide value of vegetable oil

为解决国标法测定植物油酸值、过氧化值溶剂安全性问题,以核桃油为实验材料,建立以更安全且容易获取的石油醚、二氯甲烷分别代替GB 5009.229—2016和GB 5009.227—2016中乙醚、三氯甲烷,测定植物油的酸值和过氧化值的方法,考察方法的精密度,采用国标法和所建立方法测定4种植物油的酸值、过氧化值,并对结果进行t检验,考察方法的准确度。结果表明:所建立方法平行测定了6次核桃油的酸值、过氧化值,其相对标准偏差(RSD)分别为2.055%、1.318%;国标法和本实验方法同时测定4种植物油的酸值、过氧化值p值均大于0.05,两种方法不存在显著性差异。所建立的方法精密度和准确度均较好,并且提高了检测安全性,可用于植物油的酸值和过氧化值测定。

In order to solve the problem of solvent safety in the determination of acid value and peroxide value of vegetable oil by national standard method,using walnut oil as experimental material,a method was established to determine the acid value and peroxide value of vegetable oil by replacing ethyl ether and trichloromethane in GB 5009.229-2016 and GB 5009.227-2016 with petroleum ether and dichloromethane,which were safer and easily available,respectively.The precision of the method was investigated.The acid values and peroxide values of four vegetable oils were determined by national standard method and the established method,and the results were subjected to t-test to examine the accuracy of the method.The results showed that the acid value and peroxide value of walnut oil were determined 6 times in parallel,the RSD values of the established methods were 2.055%and 1.318%,respectively.The p-values of acid values and peroxide values of the four vegetable oils by national standard method and the established method were all greater than 0.05,showing no significant difference between the two methods.The established method is characterized by better precision and accuracy,and improves assay safety,so it can be used for the determination of acid value and peroxide value of vegetable oil.