固相萃取-气相色谱-质谱法测定植物油中苯并(a)芘和苯并(e)芘

Determination of benzo(a) pyrene and benzo(e) pyrene in vegetable oil by gas chromatography-mass safter based on solid phase extraction

目的建立植物油中苯并(a)芘和苯并(e)芘的液液萃取-固相萃取-气相色谱质谱(GC-MS)检测方法,为植物油的食品安全检测提供参考。方法样品经同位素内标稀释,加氢氧化钾溶液皂化,用正己烷提取后加水除杂,再经SLH固相萃取小柱(硅胶+硅藻土)富集净化,氮吹浓缩后用气相色谱-质谱联用仪测定,内标法进行定量。结果苯并(a)芘和苯并(e)芘在0.5 ng/ml^50 ng/ml范围内线性关系良好,方法最低检出限为0.5 ng/ml,加标回收率能达到85%~98%,相对标准偏差为3.4%~5.6%(n=6)。结论该方法操作方便,灵敏准确,能满足植物油中苯并(a)芘和苯并(e)芘分析的要求。

Objective To develop an analytical method for determination of benzo（a） pyrene and benzo（e） pyrene in vegetable oil by gas chromatography-mass spectrometry（GC-MS） after liquid-liquid extraction and solid phase extraction,and provide reference for food safety determination of vegetable oil.Methods After isotope internal standard dilution and saponification of potassium hydroxide solution,the sample was extracted using hexane as solvent,cleaned-up with water,then enriched and cleaned on solid phase extraction column（SLH column,silica gel ＋ kieselgur）,concentrated by nitrogen flow and analyzed by GC-MS under selective ion monitoring mode.Results The detection limits of the method were 0.5 ng /ml.Benzo（a） pyrene and benzo（e） pyrene showed good linearity in the range of 0.5 ng /ml - 50 ng /ml,with the recoveries from 85% to 98%,and RSDs of 3.4% - 5.6%（n = 6）.Conclusion The method is simple,sensitive and accurate.It is suitable for determination of benzo（a） pyrene and benzo（e） pyrene in vegetable oil.