实验在流动载气-液滴微萃取(GF-LDME)技术的基础上增加了液滴托附装置,设计并建立了内标物释放和热解产物富集的新型联用装置,使内标物和热解产物在相同条件下完成液滴的萃取和富集,实现了各温度段间目标热解产物相对含量的纵向比较.实验利用热重模拟咖啡生豆的烘焙过程,同时利用联用装置结合气相色谱-质谱研究了咖啡生豆在热重程序升温过程中发生的热解反应及其热解产物的逸出行为.热重条件:初始温度为50℃;以10℃/min升温至500℃;空气为载气.结果表明,在100～400℃范围内共发现13个热解产物,在280～ 300℃温度段,逸出量达到峰值的热解产物包括羟基丙酮、吡啶、糠醇、γ-丁内酯和正戊醛;在300～320℃温度段,逸出量达到峰值的热解产物包括乙酸、苯酚、2-环戊烯酮和愈创木酚.建立的联用装置在热解产物的逸出行为研究中具有明显优势.
Internal standard was applied to the analysis of evolved behavior of pyrolysis products.Liquid drop supporting device of gas flow-liquid drop microextraction (GF-LDME) was improved.The coupling device used to release internal standard and enrich the pyrolysis products was established.The internal standard and pyrolysis products were extracted into liquid drop under the same conditions.Coupled the device with gas chromatography-mass spectrometer (GC-MS),the comparison of relative amount for each pyrolysis product between different temperature ranges was achieved.The evolved behavior of pyrolysis products for green coffee beans was investigated.The experiments were conducted at a flowing air rate of 200 mL/min and a heating rate of 10 ℃/min.Identification of 13 pyrolysis products between 100 ℃ and 400 ℃ and the monitoring of evolved behavior were carried out.The hydroxyacetone,azabenzene,furfuryl alcohol,γ-butyrolactone and n-valeraldehyde evolved reached to a maximum evolved quantity at 280-300 ℃,while acetic acid,phenol,2-cyclopentenone,2-methoxyphenol evolved reached to a maximum quantity at 300-320 ℃.The method has obvious advantages in the analysis of complex pyrolysis products.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%