冷冻法结合GC-MS/MS测定植物油中19种邻苯二甲酸酯类化合物

Determination of 19 Phthalate Acid Esters in Vegetable Oil by Freezing Method Combined with GC-MS/MS

为了建立一种快速、高效、便捷测定植物油中19种邻苯二甲酸酯类化合物的检测方法,对冷冻法结合GC-MS/MS检测植物油中19种邻苯二甲酸酯类化合物含量的方法进行了研究。结果表明:(1)将前处理方法中–18℃冷冻保存24 h改为–36℃冷冻保存12 h,节省了样品前处理时间;(2)与LS/T 6131—2018《粮油检验植物油中邻苯二甲酸酯类化合物的测定》方法相比,除了对邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二异丁酯、邻苯二甲酸二正丁酯、邻苯二甲酸二环己酯、邻苯二甲酸二(2-乙基)己酯、邻苯二甲酸二异壬酯和邻苯二甲酸二异癸酯8种邻苯二甲酸酯类化合物的测定外,增加了对11种邻苯二甲酸酯类化合物的测定,包括邻苯二甲酸二烯丙酯、邻苯二甲酸二(2-甲氧基)乙酯、邻苯二甲酸二(4-甲基-2-戊基)酯、邻苯二甲酸二(2-乙氧基)乙酯、邻苯二甲酸二戊酯、邻苯二甲酸二己酯、邻苯二甲酸丁基苄基酯、邻苯二甲酸二(2-丁氧基)乙酯、邻苯二甲酸二苯酯、邻苯二甲酸二正辛酯和邻苯二甲酸二壬酯;(3)与LS/T 6131—2018方法中外标法定量相比,增加了同位素内标法定量,比较了同位素内标法和外标法在测定植物油中邻苯二甲酸酯类化合物的差异。结果表明,植物油中19种邻苯二甲酸酯类化合物在GC-MS/MS上线性关系良好,外标法和内标法相关系数均大于0.990,检出限和定量限均低于标准方法,且内标法精密度和准确度优于外标法。

In order to establish a rapid,efficient and convenient method for the determination of 19 phthalate esters in vegetable oil,a method for the determination of 19 phthalate acid esters in vegetable oil by freezing method combined with GC-MS/MS was developed.The results showed that:the pretreatment method of freezing for 24 hours at-18℃was changed to freezing for 12 hours at-36℃which could reduce the sample pretreatment time.In addition to the determination of 8 phthalate ester compound in LS/T 6131-2018,this method also determined 11 phthalate ester compounds,including DAP,DMEP,BMPP,DEEP,DPP,DHXP,BBP,DBEP,DPhP,DNOP and DNP.Compared with the external standard method of LS/T 6131-2018,this method added the isotope internal standard method.GC-MS/MS was used to compare differences between the internal standard method and the external standard method in determining the content of phthalate esters in vegetable oil.The results showed that there was a good linear relationship between the chromatographic peak responses values of 19 phthalate esters in vegetable oil on GC-MS/MS and their mass concentrations.The correlation coefficients of the regression curve equations of the external standard method and the internal standard method were greater than 0.990,and the detection limit and quantitative limit were lower than LS/T 6131-2018.The method met the requirements of 19 PAEs analysis.The precision and accuracy of internal standard method are better than that of external standard method,mainly because the internal standard method can avoid the content loss in the extraction process.The experimenter can use the corresponding quantitative method according to the actual situation.