流动注射荧光法测定植物油中脂肪醛

Determination of aliphatic aldehydes in plant oils by flow injection fluorescence method

建立了流动注射荧光法测定食用植物油中脂肪醛化合物的方法。利用2-萘肼和脂肪醛化合物在酸催化作用下生成在400 nm波长处有强荧光发射的2-萘腙化合物的原理,在自制的流动注射分析仪中,以混合醛(甲醛、乙醛、正丙醛、正丁醛、正戊醛、正己醛、正庚醛、正辛醛、正壬醛)为标准物质,对催化剂、温度、时间、溶剂、2-萘肼的浓度和载流流速进行了条件优化,确定了最佳的流动注射荧光法检测食用植物油中脂肪醛化合物的方法。在该优化条件下,脂肪醛化合物测定的线性工作曲线为y=26.8x+42,相关系数0.997;该方法的相对标准偏差(RSD)在1.18%~1.89%之间,回收率在92%~113%之间,最低检出限为0.02 mmol/L(S/N=3)。因此,流动注射化学发光法具有方法简单、检测快速、数据准确等特点,可用于实际食用油样品中醛类物质的在线快速检测。

A flow injection spectrophotometry method for the determination of aldehydes content in vegetable oil was built.The standard substance was adopted by mixed equal-molar nine aldehydes（ formaldehyde,acetaldehyde,n-propanal,n-butanal,n-pentanal,n-hexaldehyde,n-heptaldehyde,n-octanal and n-nonanal）. The optimal condition for aldehydes determination was obtained by adjusting catalysts,temperature,time,solvents,flow rate,and dosage of reagent,which was suitable to the reaction of aldehydes and 2-naphthylhydrazine to produce the 2-naphthalene hydrazone derivatives under the acid action by self-made flow injection equipment with strong fluorescence-emission at 400 nm. As a result,the linear equation of aliphatic aldehydes was y = 26.8x ＋ 42（ r = 0.997）,with 1.18% ~ 1.89% of relative standard deviation（ RSD） and 92% ~ 113% of recovery rate.The limit of detection（ LOD） for this method was 0.02 mmol/L（ S/N = 3）.The method can be applied successfully to the determination of aliphatic aldehydes in plant oils with much simple way,high speed and accuracy.