Analytical difficulties encountered in the determination of ethyl carbamate, a known cancinogen, in a wide variety of wines and spirits have been overcome by spe- cific, sensitive GC/GC and CC/CC/MS methods with a rel...Analytical difficulties encountered in the determination of ethyl carbamate, a known cancinogen, in a wide variety of wines and spirits have been overcome by spe- cific, sensitive GC/GC and CC/CC/MS methods with a relatively shorter extraction procedure. The lowest detection limits were estimated to be 0. 1 and 0. 01μg/L for GC/GC and GC/GC/MS respectively. The RSD of the GC/GC method was 2. 5%.展开更多
本文通过以玉米碴为原料,酿酒酵母、嗜酸乳杆菌、枯草芽孢杆菌及纳豆芽孢杆菌作发酵剂,以单菌和组合的方式对玉米进行发酵制成玉米粉,采用气相-离子迁移谱(Gas-chromatography ion mobility spectrometry,GCIMS)和气相色谱-质谱联用(Gas...本文通过以玉米碴为原料,酿酒酵母、嗜酸乳杆菌、枯草芽孢杆菌及纳豆芽孢杆菌作发酵剂,以单菌和组合的方式对玉米进行发酵制成玉米粉,采用气相-离子迁移谱(Gas-chromatography ion mobility spectrometry,GCIMS)和气相色谱-质谱联用(Gas Chromatography-Mass Spectrometry,GC-MS)方法对发酵玉米粉的挥发性风味成分进行分析。结果表明,GC-IMS共检出68种风味物质,包括醛类12种、醇类18种、酯类11种、酮类11种以及6种杂环类;根据图谱差异分析发现,发酵后玉米粉风味物质均发生变化,其醇类、酯类和酸类物质含量相对提高。GC-MS共检出59种风味物质,包含13种醛类、12种酯类、15种醇类、7种酸类、6种酮类和7种杂环类物质。两种技术共同检测出29种风味物质,其中正癸醛等10种醛类、5种醇类、2-壬酮、2-庚酮、己酸乙酯、甲酸甲酯、丁酸乙酯及4种酸类物质为发酵玉米粉的主要风味物质。根据香气含量分析,对比未发酵玉米粉,自然发酵水果香含量提高了24.64%,酿酒酵母发酵水果香和酒香含量分别提高了30.05%、85.05%,嗜酸乳杆菌发酵水果甜香和奶油蜂蜜香含量分别提高了36.56%、90.36%,枯草芽孢杆菌和纳豆芽孢杆菌发酵水果甜香花及苦杏仁香含量分别提高了18.05%、15.59%和38.68%、38.02%,组合发酵水果甜香花、草香含量分别提高了53.53%、48.08%,表明经过发酵制得的玉米粉风味独特。展开更多
本文建立同时检测3种4(3H)-喹唑啉酮滥用物质甲喹酮、依他喹酮和甲氧喹酮的GC-MS与GCMS/MS分析方法,并分别应用于实际案件中对疑似毒品与滥用人员毛发进行分析。使用选择离子监测模式(selected ion monitoring,SIM)和多反应监测模式(mul...本文建立同时检测3种4(3H)-喹唑啉酮滥用物质甲喹酮、依他喹酮和甲氧喹酮的GC-MS与GCMS/MS分析方法,并分别应用于实际案件中对疑似毒品与滥用人员毛发进行分析。使用选择离子监测模式(selected ion monitoring,SIM)和多反应监测模式(multiple reaction monitoring,MRM)分别对甲喹酮、依他喹酮和甲氧喹酮的标准品溶液进行分析,确定三种物质的特征碎片离子和特征离子对,并利用所建立的两种方法分别对实际案例中的疑似毒品和毛发样本进行检验。建立的GC-MS分析方法在送检的疑似毒品中检出甲喹酮、依他喹酮和甲氧喹酮成分且含量分别为11、4.3、2.5μg/mg,建立的GC-MS/MS分析方法在送检的毛发中检出甲喹酮、依他喹酮和甲氧喹酮成分且含量分别为148 ng/mg、565 pg/mg、58.2 ng/mg。本研究建立的GC-MS及GC-MS/MS检测方法具有简单、快速、准确的特点,可为疑似毒品与滥用人员毛发中甲喹酮、依他喹酮和甲氧喹酮的检测提供可靠的科学依据。展开更多
文摘Analytical difficulties encountered in the determination of ethyl carbamate, a known cancinogen, in a wide variety of wines and spirits have been overcome by spe- cific, sensitive GC/GC and CC/CC/MS methods with a relatively shorter extraction procedure. The lowest detection limits were estimated to be 0. 1 and 0. 01μg/L for GC/GC and GC/GC/MS respectively. The RSD of the GC/GC method was 2. 5%.
