不同裂解条件对天冬酰胺主要裂解产物的影响  

Influences of Pyrolysis Conditions on the Major Pyrolytic Products of Asparagine

作　　者：郝菊芳[1,2] 郭吉兆[2] 谢复炜[2] 夏巧玲[2] 谢剑平[2] 

机构地区：[1]中国科学院大连化学物理研究所国家色谱中心,辽宁大连116023 [2]中国烟草总公司郑州烟草研究院,河南郑州450001

出　　处：《分析测试学报》2013年第5期519-526,共8页Journal of Instrumental Analysis

基　　金：国家烟草专卖局科技重大专项(110200902002)

摘　　要：采用在线裂解气相色谱-质谱联用技术(Py/GC-MS)对不同条件下天冬酰胺的主要裂解产物进行分析,并通过裂解同位素标记样品,计算主要含氮裂解产物中的同位素比例,推测其形成途径,研究裂解条件对主要裂解产物形成的影响。结果表明:温度对天冬酰胺裂解影响较大,主要裂解产物在低温和高温下生成量变化较大。300℃时,马来酰亚胺和琥珀酰亚胺为主要的裂解产物,300～600℃时生成量显著增加,600～900℃时马来酰亚胺生成量缓慢增加而琥珀酰亚胺逐渐降低;随着温度升高,酸类和酰胺类物质生成量持续增加;腈类和吡咯类物质在高温下生成量明显增加。此外,温度对含氮裂解产物的形成途径也有较大影响。马来酰亚胺、乙酰胺在低温下N主要来源于标记的酰胺N,而在高温下主要来源于未标记的氨基N。氢氰酸、乙腈和丙烯腈中的N原子均主要由未标记的氨基转变而来,且随着温度升高,这种生成途径所占比例越高。而裂解气氛和裂解时间对天冬酰胺主要裂解产物的生成量及途径影响较小。In this study,the pyrolysis vapors of asparagine under different pyrolytic conditions were analyzed by analytical pyrolysis/gas chromatography-mass spectrometry（Py/GC-MS）.In addition,by using the amide 15N-labeled asparagine sample and analysis of label incorporation of the major nitrogen-contained compounds,the influence of pyrolysis conditions on the formation pathways of the major pyrolysis products of asparagine were elucidated.The results indicated that pyrolysis temperature has a significant impact on the decomposition of asparagine.The yields of major products at low-and high-temperature are strikingly different.The yields of maleimide and succinimide,which are the predominant pyrolysis products of asparagine,increased strikingly as the pyrolysis temperature increased from 300 ℃ to 600 ℃,while in contrast,from 600 ℃ to 900 ℃,the peak area of maleimide increased slowly but succinimide starts to decrease.The yields of amides and acidic compounds increased monotonically with the increase of the pyrolysis temperature,and the formation of nitriles and pyrroles were favored at higher heating temperatures.Furthermore,pyrolysis temperature has a significant effect on the formation pathways of the major pyrolysis products of asparagine.Most of the nitrogen in maleimide and acetamide originate from the 15N-labeled amide group of asparagine at low temperature,while from the unlabeled amino group at high temperature.The nitrogen atoms of the three nitrile compounds,hydrogen cyanide,acetonitrile and acrylonitrile are mainly from the unlabeled amino group,especially at higher temperature.By contrast,the influences of pyrolysis atmosphere and time on the yields and formation pathways of the major products of asparagine are much less.

关 键 词：天冬酰胺 热裂解 气相色谱-质谱联用 裂解条件 影响 

分 类 号：O657.63[理学—分析化学] O629.7[理学—化学]