维生素E热裂解行为研究

 组合应用热裂解-冷进样-气质联用( Py-CIS-GC/MS)技术,对维生素E在无水空气、9%氧氮混合气、氦气中,300,600,900℃下的裂解产物进行研究,结果显示:①维生素E在各个裂解气氛及裂解温度下共有的裂解产物有壬醛、1-甲基-2-戊基-环丙烷、维生素E;②对于在900℃和600℃时的裂解,在同一裂解温度下,随着裂解气氛中含氧量的减少,烯烃类物质种数减少,质量分数下降;烷烃类物质其种数虽然减少,但质量分数却明显增大;酮、醛、醇、酯、呋喃类香味物质随着裂解气氛中含氧量的减少其个数减少,质量分数下降;对于同一个裂解气氛,随裂解温度的降低其裂解产物中烯烃类、烷烃类物质种数呈减少趋势且含量下降;酮、醛、醇、酯、呋喃类物质产物种数和含量变化不大;③300℃时裂解产物以维生素E的原形转移为主,并生成了壬醛、烷烃类物质等;④裂解温度在600℃及900℃时维生素E原形转移的量差别不大,平均质量分数约为17.80%;而在300℃时,在无水空气、氧氮混合气、氦气氛围下转移的量分别为90.24%、84.61%和75.60%.

Study on pyrolysis of vitamin E

The pyrolysis products of vitamin E at 300℃,600℃ and 900℃ in atmosphere of air,nitrogen of 9% oxygen and helium respectively was analyzed by pyrolysis- cryo-trap(CIS)-gas chromatography-mass spectrometry ( PY-CIS -GC/MS).The results showed that: ①Vitamin E at all pyrolysis atmospheres and temperatures have the following pyrolysis products:nonanal,cyclopropane, 1-methyl-2-pentyl-,vitamin E;②Pyrolysis products of vitamin E at 900℃ and 600℃,for the same pyrolysis temperature,with decreasing of pyrolysis oxygen content,the quantity and content of alkenes decrease,and the quantity decrease and the content increase of alkanes,while the quantity and content of ketones,aldehydes,alcohols,esters,furans decrease;with decreasing of pyrolysis temperature,for the same pyrolysis atmosphere,the quantity and content of alkenes,alkanes decreas while the quantity and content of ketones,aldehydes,alcohols,esters,furans change little;③At 300℃,the main pyrolysis products is vitamin E,nonanal and alkanes are also included;④Vitamin E transferred to its own pyrolysis products directly shows little difference in content at 600℃and 900℃,the average content is 17.80%;in air,nitrogen of 9% oxygen and helium this content at 300℃ are:90.24%,84.61% and 75.60%respectively.