紫外分光光度计检测十二烷基苯磺酸钠鉴别潲水油的方法研究

Distinguishment of Hogwash Fat through Determination of Sodium Dodecylbenzene Suifnate by Ultraviolet-Visible Spectrophotometry

建立了潲水油中十二烷基苯磺酸钠(SDBS)的检测方法,样品经高纯水提取、三氯甲烷萃取、亚甲蓝显色后,以紫外分光光度法进行测定。考察了提取温度、提取时间等因素的影响。实验结果表明,水对食用油中SDBS的最佳提取时间为2 h,温度为50℃,检测波长为645 nm。方法检出限(LOD)为0.1μg/kg。加标量分别为1.0、5.0、10.0、20.0μg/kg时的回收率为94%～96%,相对标准偏差(RSD)均小于5%。5组实际样品的检测结果显示,潲水油中SDBS的残留量平均值为19.19μg/kg,优质食用油中SDBS的平均含量为0.35μg/kg。潲水油中SDBS的含量有很大差别,但总体均高于优质食用油中的含量,方法可用于潲水油和食用植物油的鉴别。

A new method was established for the determination of sodium dodecylbenzene suifnate（SDBS） in hogwash fat by ultraviolet-visible spectrophotometry.SDBS was extracted with distilled water,and reextracted with trichloromethane.The SDBS was determined after the coloration by methylene blue in the hogwash fat.The experimental factors such as extraction temperature and time were investigated.The optimal conditions were as follows：extraction time：2 h,extraction temperature：50 ℃ and detection wavelength：645 nm.Under the optimal conditions,the detection limit of SDBS was 0.1 μg/kg.The recoveries of SDBS in oil sample at spiked levels of 1.0,5.0,10.0,20.0 μg/kg were in the range of 94%-96% with RSDs less than 5%.The results of 5 groups of actual samples showed that the average of SDBS residues in hogwash fat was 19.19 μg/kg while the SDBS content in high-quality edible oil was 0.35 μg/kg.The testing results of actual samples showed that the SDBS contents in the hogwash fat were of big differences,but the contents were overall higher than those of the edible oil.The method could be used in the discrimination of hogwash fat.