同位素内标结合真空浓缩气相色谱-质谱法测定辣条中4种多环芳烃标志物

Determination of 4 polycyclic aromatic hydrocarbons in spicy strips by vacuum concentration coupled with isotope dilution gas chromatography-mass spectrometry

目的建立基于同位素内标稀释测定辣条中[艹屈]、苯并[a]蒽、苯并[b]荧蒽、苯并[a]芘4种多环芳烃标志物(4 polycyclic aromatic hydrocarbons,PAH4)的检测方法,并对市售辣条中PAH4含量进行调查分析。方法辣条样品充分粉碎研磨后用正己烷提取,真空浓缩,1.5 mol/L氢氧化钾乙醇溶液皂化,固相萃取柱净化,经DB-EUPAH色谱柱(20 m×0.18 mm,0.14μm)分离后用气相色谱-质谱法检测,同位素内标定量。结果辣条中PAH4不同浓度水平的加标回收率为91.0%~103.5%,相对标准偏差为1.89%~6.73%(n=6)。方法定量限为1.0μg/kg,检出限为0.30μg/kg。采用本方法对市售的27份辣条进行测定,4种多环芳烃标志物总量范围为1.35~11.44μg/kg,检出率为100%。结论本方法溶剂用量少,简便快速准确,净化效果及空白控制均较好,满足辣条中PAH4含量检测要求。

OBJECTIVE A method based on isotope internal standard dilution was established for the determination of four polycyclic aromatic hydrocarbons(PAH4)including chrysene,benzo[a]anthracene,benzo[b]fluoranthene and benzo[a]pyrene in spicy strips sold in the markets.METHODS The hot strips were homogenized and the target compounds were extracted with n-hexane,concentrated in vacuum,saponified and purified by solid phase extraction column,then the pretreated samples were separated by DB-EUPAH column(20 m×0.18 mm,0.14μm),detected by gas chromatography-mass spectrometry(GC-MS)and quantified by internal standard of isotope.RESULTS The recoveries of PAH4 in different concentration levels of hot noodles were 91.0%-103.5%,and the relative standard deviation(RSD)was 1.89%-6.73%(n=6).The detection limit was 0.30μg/kg and the quantitative limit was 1.0μg/kg.The content of PAH4(sum)in 27 collected samples ranged from 1.35μg/kg to 11.44μg/kg,and the detection rate was 100%. CONCLUSION With less solvent consumption,good purification effect and blank control,the method is simple,rapid and accurate and meets the detecting requirements of PAH4 in hot strips.