【摘要】 应用直接溶剂萃取/气相色谱-质谱技术,建立了辐照牛肉中2-十二烷基环丁酮(2-Dodecylcyclobu-tanone,2-DCB)的快速检测方法。5 g牛肉糜与7 g无水Na2SO4混合均匀后,加入150 mL乙腈,搅拌提取2 min,提取液过滤转移至500 mL圆底烧瓶中,提取重复2次,将提取液旋转蒸干,用正己烷清洗烧瓶并收集,定容至50 mL,取10 mL氮吹浓缩至1 mL,用硅胶固相萃取小柱(1 g,6 mL)净化,淋洗液经氮气吹干后用正己烷定容至1 mL,取1μL供气相色谱-质谱测定。本方法检出限为0.004 mg/kg,定量限为0.01 mg/kg;牛肉糜中2-DCB添加浓度在0.01～0.50 mg/kg范围内的回收率为87.9%～91.6%,相对标准偏差小于7%,样品前处理仅需60～90 min。采用本方法对辐照剂量为0.5～7.0 kGy的牛肉进行检测,表明辐照剂量与牛肉中2-DCB含量存在线性相关关系(y=0.0608x-0.0004,相关系数R2=0.9899)。更多还原

【Abstract】 A new rapid analytical method based on direct solvent extraction(DSE)/gas chromatography-mass spectrometry(GC-MS) was developed to analyze 2-dodecyclobutanone(2-DCB) to detect γ-ray irradiated beef.A 5 g sample of ground beef patties was homogenized with 7 g of anhydrous sodium sulfate and blended with 150 mL acetonitrile using a blender for 2 min.The extract solvent was carefully transferred to a 500 mL round-bottom flask through filter paper.And the procedure repeated for two times.Then,the extraction solutions were evaporated to dryness using a rotary evaporator.The round-bottom flask was washed with hexane,and the solution was collected into a 50 mL volumetric flask.The 10 mL hexane aliquot was dried to 1 mL via nitrogen stream and then purified with a silica cartridge(1 g,6 mL).The elution was concentrated to 1 mL with a nitrogen stream,and 1 μL was injected into the gas chromatography-mass spectrometer.The limit of detection and quantitation was 0.004 and 0.01 mg/kg,respectively.The procedure was evaluated with a recovery test in six samples spiked with 2-DCB at 0.01 and 0.5mg/kg of ground beef,resulting in 87.9%-91.6% recoveries with mostly less than 7% RSD.The operation time for sample preparation was about 60 to 90 min.The method was used to detect 2-DCB in ground beef irradiated at 5 targeted absorbed doses of 0.5,1.0,3.0,5.0 and 7.0 kGy and the concentration of 2-DCB increased linearly with dose(y=0.0608x-0.0004,R2=0.9899).更多还原