摘要
建立了固相萃取(SPE)净化、程序升温进样结合气相色谱-氢火焰离子化检测器(PTV-GC-FID)定量分析橄榄油中饱和烃矿物油(MOSH)和芳香烃矿物油(MOAH)污染残留的方法。样品经正己烷溶解后,利用环氧化反应结合自制的分子筛SPE柱和0.3%AgNO_3硅胶SPE柱交替净化方式,消除了样品中脂质、蜡酯、烯烃、天然烷烃等干扰,并实现MOSH和MOAH的有效分离,氮吹浓缩后,经程序升温进样口大体积进样注入GC-FID分析,外标法定量。优化了环氧化试剂用量、环氧化反应时间、固相萃取洗脱体积等实验参数。结果表明,矿物油标准参考物Gravex 913润滑油在2.0~500.0 mg/L范围内呈良好线性关系,MOSH和MOAH的检出限分别为1.0和0.3 mg/kg,定量限分别为3.0和1.0 mg/kg,加标回收率分别为93.2%~103.7%和78.5%~81.3%,相对标准偏差分别为2.7%~5.0%和2.9%~4.0%。本方法净化效果好、试剂用量少、操作简单、检出限低,能有效分离植物油中MOSH和MOAH,适用于橄榄油中矿物油的定量检测。
A method for quantitative analysis of mineral oil saturated hydrocarbons( MOSH) and aromatic hydrocarbons( MOAH) in olive oils by solid phase extraction( SPE) combined with programmed temperature vaporizer-gas chromatography-flame ionization detection( PTV-GC-FID) was established. The samples were dissolved in hexane,purified by the means of epoxidation combined with self-made molecular sieve SPE column and 0.3% silver nitrate silica SPE column alternating purification mode,in which way the interfering substances of lipids,wax esters,olefins and natural alkenes were removed,and the MOSH and MOAH fractions were effectively separated. The fractions were then concentrated by nitrogen,analyzed by the GC with large volume injection,separated by the capillary columns of DB-1,determined by a flame ionization detector,and quantified by external standard method. In addition,the key experimental parameters were optimized,including the amount of epoxidation reagent( mC PBA),epoxidation reaction time and elution volume. Under the optimized experimental conditions,Gravex913 lubricating oil showed good linearity as a standard reference of mineral oil in the ranges of 2.0-500.0 mg/L,the limits of detection( LOD) of MOSH and MOAH fractions were 0.3 mg/kg and 1. 0 mg/kg,the limits of quantification( LOQ) were 1. 0 mg/kg and 3. 0 mg/kg,respectively. The spiked recoveries of MOSH and MOAH fractions were in the range of 93.2%-103.7% and 78.5%-81. 3% at three spiked levels with the relative standard deviations( RSDs) of 2. 7%-5. 0% and 2.9%-4.0%(n = 6). The established method has many advantages such as good purification effect,low reagent consumption and low detection limit,and is suitable for the separation and quantification of MOSH and MOAH in olive oils.
引文
1 European Food Safety Authority(EFSA)(2012).Scientific Opinion on Mineral Oil Hydrocarbons in Food.EFSA J.10(6):2704,1-185
2 Nestola M,Schmidt T C.J.Chromatogr.A,2017,1505:69-76
3 Grob K.J.Consum.Prot.Food Saf.,2014,9(3):213-219
4 Tarnow P,Hutzler C,Grabiger S,Sch9n K,Tralau T,Luch A.Plos One,2016,11(1):1-15
5 Purcaro G,Barp L,Moret S.Anal.Methods,2016,8(29):5755-5772
6 ZHANG Min,CAO Wan-Xin,SHI Xuan-Ming,ZHANG Li,CHEN Yan,FAN Ming-Liang.Chin.Oil Fat,2015,40(3):62-65张闽,曹万新,史宣明,张骊,陈燕,范明亮.中国油脂,2015,40(3):62-65
7 Biedermann M,Grob K.J.Chromatogr.A,2012,1255:76-99
8 Biedermann M,Mccombie G,Grob K,Kappenstein O,Hutzler C,Pfaff K,Luch A.J.Consum.Prot.Food Saf.,2017,12(6):363-365
9 Biedermann M,Fiselier K,Grob K.J.Agric.Food Chem.,2009,57:8711-8721
10 Zurfluh M,Biedermann M,Grob K.J.Consum.Prot.Food Saf.,2014,9:61-69
11 Zoccali M,Barp L,Beccaria M,Sciarrone D,Purcaro G,Mondello L.J.Sep.Sci.,2016,39(3):623-631
12 Moret S,Barp A,Grob K,Lanfranco S C.Food Chem.,2011,129:1898-1903
13 Wrona M,Pezo D,Nerin C.Food Chem.,2013,141:3993-3999
14 Fiselier K,Fiorini D,Grob K.Anal.Chim.Acta,2009,634(1):102-109
15 Fiselier K,Grundb9ck F,Sch9n K,Kappenstein O,Pfaff K,Hutzler C,Luch K,Grob K.J.Chromatogr.A,2013,1271(1):192-200
16 Moret S,Barp L,Purcaro G,Lanfranco S C.J.Chromatogr.A,2012,1243:1-5
17 XIANG Hai,DING Ran-Feng,ZHANG Yong-Kui,LV Ming-Zhi,ZHAO Feng-Zhi.J.Sichuan Univ.(Nat.Sci.Editor.),2011,48(2):415-420向海,丁冉峰,张永奎,吕明智,赵风知.四川大学学报:自然科学版,2011,48(2):415-420
18 ZHANG Meng,ZHAO Hong,WANG Hui-Tong,ZHU Zhong-Yun,WANG Pei-Rong.Petrol.Explor.Dev.,2003,30(5):83-85张萌,赵红,王汇彤,朱忠云,王培荣.石油勘探与开发,2003,30(5):83-85
19 YANG Chun-Yan,ZHANG Jiu-Kui,KE Run-Hui,WANG-Shuo,YIN Jian-Jun,SONG Quan-Hou.China Food Addit.,2018,1:165-174杨春艳,张九魁,柯润辉,王烁,尹建军,宋全厚.中国食品添加剂,2018,1:165-174
20 Biedermann M,Grob K.J.Chromatogr.A,2012,1255:56-75
21 GB/T 27404-2008,Criterion on Quality Control of Laboratories-Chemical Testing of Food.Naional Standard of the People's Repbulic of China实验室质量控制规范食品理化检测.中华人民共和国国家标准.GB/T 27404-2008
22 Summary Minutes of the Meeting of the Standing Committee on the Food Chain and Animal Health.Brussels,20 June 2008