有机溶剂稀释与气相色谱-燃烧-同位素质谱(GC-C-IRMS)联用测定食醋中乙酸的δ^(13)C  

Determination of Carbon Isotope Ratio of Acetic Acid in Vinegar by GC-C-IRMS Coupled with Organic Solvent Dilution

作　　者：钟其顶[1,2,3] 王道兵[2,3] 孟镇[2,3] 熊正河[2,3] 王敏[1] 

机构地区：[1]天津科技大学,天津300457 [2]中国食品发酵工业研究院,北京100027 [3]全国食品发酵标准化中心,北京100027

出　　处：《质谱学报》2014年第4期372-377,共6页Journal of Chinese Mass Spectrometry Society

基　　金：国家自然科学基金(31101333);国家支撑计划项目(2012BAK17B11);科技部国际合作项目(2011DFA33270)资助

摘　　要：食醋中乙酸的碳-13比值(δ13 C)与食醋原料有密切关联,通过测定乙酸中δ13 C可对食醋原料进行溯源。本工作建立了有机溶剂稀释法与气相色谱-燃烧-稳定同位素比值质谱(GC-C-IRMS)联用法测定食醋中乙酸的δ13 C。在乙酸浓度为2%~99.9%的模拟样品测试中获得了稳定的检测结果;同一样品中乙酸的δ13 C重复测定16次的标准偏差小于0.15‰;参与欧盟同位素实验室间能力测试时,该方法的测定结果与其中5个国际实验室测定平均值差异为0.17‰。该方法的精密度和稳定性好、准确性高、操作简便快速,适合在食醋真实性技术中应用和推广。Stable carbon isotope composition （δ13C） of acetic acid is a valuable character as tracer for raw fermentation material of vinegar, however, the analytical technique still re- mains be estimated. Now, a rapid method for the determination of δ13C of acetic acid in vin- egar by gas chromatography-combustion_isotope ratio mass spectrometry （GC-C-IRMS） coupled with a capillary column was developed. Results demonstrate that the method above is stable with a standard deviation （la） lower than 0.15‰ （n= 16） with which other organic compounds in vinegar can be ignored, and the variation of δ13C detormination is very small __while acetic acid range from 2 % to 99.9 %. We take participant in a FIT Proficiency Testing Scheme for an inter-laboratory comparison study of carbon isotopic methods of acetic acid, and the difference is 0.17‰ between the measurement and the mean value of 5 laboratories. This method has an advantage of easy and rapid operating, and which is applicable for δ13C analysis of acetic acid for vinegar authenticity control.

关 键 词：食醋 乙酸 气相色谱-燃烧-稳定同位素比值质谱(GC-C-IRMS) 碳-13 稳定同位素比值 

分 类 号：O657.63[理学—分析化学]