FTIR法对准格尔煤两级分次萃取物的分析

FTIR analysis of fractional extracts from Zhunge'er bituminous coal

采用石油醚和CS2溶剂进行两级分次萃取的方法，以FTIR为分析测试手段，研究了准格尔煤中可溶分子的溶出行为．研究结果表明：两种溶剂的累积萃取率曲线在特殊时间段均存在两个梯级；由红外谱图和萃取率曲线可基本判别出特定分子的溶出时间；石油醚萃取物谱图中表征脂肪族2951—2858cm^-1的吸收峰总体呈大小交替变化；而CS2萃取阶段萃取物的红外谱图可分为3个部分，每一部分谱图在3410cm^-1处反映氢键缔合的-OH（或-NH）及酚、醇、羧酸和过氧化物等的吸收峰总体变化不大，而1300～1100cm^-1处的酚、醇和醚组分以及860，750cm^-1处的取代芳烃和1730cm^-1处的吸收峰变化明显，总体都呈减小的趋势；CS2与石油醚萃余煤作用36h后，某段特定链长的脂肪烃爆发性大量溶出．

To investigate the universalism and specialty of the solubilization behavior of small organic molecules in coal, Zhunge＇ er coal was extracted with petroleum ether （PE） and sampled in batches, and then the PE - residue was extracted with CS2 and sampled in batches. The PE and CS2 soluble components were analyzed using FTIR. Then, peak area ratios of some typical FTIR absorption peaks were schemed against extraction time. The results show that the curves of accumulative extraction yield presents two ladders in specific time quantum. Seen from the FTIR spectra and extraction yield curves, it can be clearly estimated the time coal and solvents reacted. Specific small molecules will dissolve in special time intervals explosively and massively. It is interesting that the peaks near 2 951 - 2 858 cm^-1 represented aliphatics change alternately in the FTIR spectra of extract extracted with PE. The FTIR spectra of the second stage can be divided into three parts, absorption peaks change obviously and reduce successively except the peaks near 3 410cm^-1 represented associated hydrogen bond--OH （or-NH）, phenols, alcohols, carboxylic acid and peroxidates, etc. in each part. After CS2 and the PE - residue reacted for 36 h, some specific long-chain alkanes dissolve explosively.