电导率法快速鉴别地沟油的试验研究

Experimental Study on the Rapid Identification of Swill-cooked Dirty Oil by Conductivity Method

通过试验研究用电导率法快速鉴别地沟油，探讨不同操作条件对测定结果的影响。测取不同水油比、震荡时间、温度、油脂种类等因素下萃取水相电导率，选择最佳的操作条件，测量不同种类油品的电导率，半定量分析食用油是否掺伪。结果表明室温条件下，震荡时间30s，水油比4：1，静沉15min时，电导率最大，检测结果最灵敏，地沟油、使用过的食用油、食用油水相电导率分别为67．73～138．87μS／cm、30．54～42．56μS／cm、11．52～19．63μS／cm。如果测定油脂电导率大于45．00μS／cm，可以断定其掺伪。

Rapid identification of swill-cooked dirty oil by conductivity method was studied; influence of different operating conditions on the determination result was discussed. The effects of oil/water ratio, oscillation time, temperature, and oil type on conductivity were investigated. The best operating conditions were determined. Through measuring water conductivity of different kinds of oil, semi-quantitative analysis of edible oil was carried out to judge whether the edible oil was adulterated. The results show that under the condition of normal temperature, shocked mixing time 30 s, the ratio of water to oil 4 ： 1 and still settlement 15 min, the conductivity is the largest and the testing result is the most sensitive, the conductivities of swill-cooked dirty oil, used oil and edible oil are 67.73～138.87 μ S/cm, 30.54～42.56 μ S/cm andll.52～19.63 μS/cm. If the conductivity of the oil is more than 45.00 μS/cm, the oil can be identified adulteration.