基于Py-GC×GC-qMS的玉米芯热解产物在线检测

利用热裂解-全二维气相色谱-质谱联用（Py-GC×GC-qMS）仪对玉米芯不同温度下热解产物进行在线分析。研究结果表明：玉米芯在550℃下热解18 s，GC×GC-qMS共检测到191种化合物，包括醇、酸、醛、酮、酯、呋喃类、碳氢化合物、酚类、含氮类和糖类等。主要化合物包括2，3-二氢-苯并呋喃、1，6-脱水-β-d-吡喃葡萄糖和糠醛，其GC含量分别为9.15%、8.80%和5.21%；而GC-qMS仅检测到58种化合物，且未检测到糖类化合物。玉米芯热解产物的种类随着温度的升高逐渐增加，在550℃时达到稳定值。温度对醛类、酮类和呋喃类化合物的影响并不明显，GC含量分别在450、550和500℃时达到最大，分别为4.80%、13.57%和21.01%；醇类、酸类和酯类化合物易在低温条件下形成；碳氢化合物易在高温条件下形成，600℃时GC含量为10.77%；酚类呈现出先增加后减少的趋势，450℃时GC含量最大为23.77%；温度的升高对含氮类和糖类GC含量的影响并不明显。

On-line Detection of Corncob Rapid Pyrolysis Products Based on Py-GC×GC-qMS

The pyrolysis products of corncob at different temperatures were analyzed on-line by using the pyrolysis-comprehensive two-dimensional gas chromatography-mass spectrometry(Py-GC×GC-qMS). The results showed that the 191 compounds were detected by GC×GC-qMS, including alcohols, acids, aldehydes, ketones, esters, furans, hydrocarbons, phenols, nitrogens and sugars when the corncob was pyrolyzed at 550℃ with 18 s. The main compounds included benzofuran, 2, 3-dihydro-, 1, 6-anhydro-beta-d-talopyranose and furfural, with GC contents of 9.15%, 8.8% and 5.21%, respectively. However, GC-qMS detected only 58 compounds, and no sugars were detected. The types of corncob pyrolysis products gradually increased with temperature increasing, reaching a stable value at 550℃. The influence of temperature on the contents of aldehydes, ketones and furans was not obvious, and the GC contents reached the maximum at 450, 550 and 500℃, which were 4.80%, 13.57% and 21.01%, respectively. Alcohols, acids and esters were easily be formed at low temperatures. Hydrocarbons were more easily be formed at high temperature, and the GC content was 10.77% at 600℃. The contents of phenols increased first and then decreased, and the maximum GC content was 23.77% at 450℃. The effect of temperature increase on the GC content of nitrogens and sugars was not obvious.