盐辅助分散液液微萃取/GC-MS/MS检测腐乳、酸乳和面包中的氨基甲酸乙酯

Determination of Ethyl Carbamate in Fermented Bean Curd, Yoghurt and Bread by GC-MS/MS with Salt Assisted Liquid Microextraction

建立了盐辅助分散液液微萃取(Salt assisted dispersible liquid-liquid microextraction,SADLLME)/气相色谱串联质谱法(Gas chromatography-tandem mass spectrometry,GC-MS/MS)检测腐乳、酸乳和面包中的氨基甲酸乙酯(Ethyl Carbamate,EC)的新方法。取1 g腐乳(3 g面包或酸乳)样品于50 mL离心管中,加入浓度为10.0μg/mL的EC-d5乙醇溶液50μL,水30 mL,蛋白沉淀剂A、B液各1 mL,漩涡混匀,离心,将上层清液倾入至另一50 mL离心管中,加入硫酸钠7 g,振荡溶解,注射针快速注入二氯甲烷800μL,漩涡1 min,离心,取下层有机相,经极性柱分离、多重反应监测(MRM)方式GC-MS/MS检测。考察方法在浓度为5~1000 ng/mL的范围内线性良好(R^2=0.9988),检出限(LOD)为0.9μg/kg,定量限(LOQ)为2.8μg/kg,加标回收率为97.02%~123.32%,相对标准偏差为2.10%~11.77%。该方法样品处理简单、成本低廉,方法准确、可靠,检出限低,可满足固态、半固态发酵食品中EC检测需要。

A new method for the determination of ethyl carbamate(EC)in fermented bean curd,yoghurt and bread was developed by gas chromatography-tandem mass spectrometry(GC-MS/MS)with salt assisted dispersing liquid-liquid microextraction(SADLLME).1 g fermented bean curd(or 3 g bread or yoghurt)sample was put into 50 mL centrifuge tube and 50μL of EC-d5 ethanol solution with concentration of 10.0μg/mL,30 mL of water,1 mL of protein precipitant A and B respectively were added.After vortex blending and centrifuging,the supernatant was poured into another 50 mL centrifuge tube;Then 7 g of sodium sulfate was added and dissolved by shaking;Next,the sample solution was injected quickly with 800μL of dichloromethane and vortexed for 1 min,and then separated by centrifugation.The organic phase at the bottom was used for GC-MS/MS analyzing through chromatographic separation with a polar column and mass detection on multi reaction monitoring(MRM)mode.The method was good linear in the concentration range of 5~1000 ng/mL with R^2>0.9988.The limit of detection(LOD)was 0.9μg/kg and the limit of quantitation(LOQ)was 2.8μg/kg.The recoveries were 97.02%~123.32%and the relative standards deviations(RSD)were 2.10%~11.77%.The method is simple,cheap,accurate and reliable,and low detection limit,which can meet the needs of EC detection in solid and semi-solid fermented food.