电导率测定法鉴别地沟油的研究及其应用

Research on Identification of Hogwash Oil by Conductivity and Its Application

食用油本身是不导电物质,而使用过的地沟油含有大量食盐、调味品等可电离物质。故可通过测定食用油的电导率鉴别是否掺入地沟油。用去离子水提取油脂得到油脂水提物,再通过测定水提物电导率鉴别油脂是否掺入地沟油。结果表明,合格食用油电导率在10μs/cm左右,而地沟油电导率为80.7μs/cm,远远高于合格食用油。将地沟油以不同比例与食用油混合,测定电导率回归方程为Y=71.927X+12.641,R2=0.999 7。此法可用于地沟油的鉴别且简单、有效。并利用此法对成都市售散装食用油掺入地沟油情况进行调查,为市场监管部门提供监管建议。

Edible oil is not electrically conductive substance, Hogwash oil contains a lot of salt, spices and other ionizable substances. Therefore, by the determination of the edible oil conductivity can identification whether it mixed with hogwash oil. The results show that conductivity of qualified edible oil was about 10 μs/cm. The conductivity of the hogwash oil was 80.7μs/cm, far higher than the qualified edible oil. Measured the conductivity of qualified edible oil that mixed with hogwash oil in different proportions. The regression equation was Y =71.927X＋12.641, R2=0.999 7.So, this method could be used to identification the hogwash oil and was simple and effective. Investigate situation of edible oil in bulk mixed with hogwash oil method on Chengdu by this method, provided supervision recommended for market supervision department.