红外光谱分析中样品处理方法的改进

The Improvement of Sample Preparation for Infrared Spectroscopy Analysis

介绍了液体和固体样品的常规制样方法 ;指出了其中最常用的方法———压片法和液膜法的不足之处 ;提出了一种改进的制样方法 ,即以廉价的空白KBr压片作片基 ,通过液膜法或浸渍法制样。对于低沸点液体样品 ,以两片空白KBr压片代替晶体盐窗 ,模拟液体池窗片液膜法制样 ;对于高沸点液体样品 ,将样品用挥发性有机溶剂稀释 ,采用浸渍法制样 ,即把空白KBr压片在稀释后的溶液中浸渍后挥发掉有机溶剂制样 ;对于固体样品 ,将其溶解于挥发性有机溶剂 ,浸渍法制样。与按常规制样方法所获得的红外光谱图进行比较 ,这种改进的制样方法所得谱图 ,能达到定性分析的要求 。

Routine preparation methods of liquid and solid samples for IR analysis are introduced, deficiencies of conventional KBr pellet and liquid film most often used are pointed out and a modified preparation method of sample is put forward, i.e. preparing a liquid film by using two blank KBr pellets or by dipping blank KBr pellet into solution which is the mixture of sample and low boiling point organic solvent. For low boiling point liquid sample, a liquid film is prepared by using two blank KBr pellets; for high boiling point liquid sample, dipping a blank KBr pellet is used; for solid sample, dipping a blank KBr pellet is used as well. From the comparison of routine and modified preparation methods, this new method can meet the need of qualitative analysis and overcome the deficiencies of conventional KBr pellet and liquid film.