go to jove.com

HIGH SCHOOL

Chemistry

Concept Videos

Analytical Chemistry

This is a free preview. For full access

Molecular Vibrational Spectroscopy

ATR Infrared Spectroscopy for Material ID

Description

ATR infrared spectroscopy is a method for identifying the composition of materials. It is used in chemistry, materials science, forensic science, and other areas where sample characterization is needed. The technique is useful because it usually needs little to no sample preparation and can be applied to many kinds of sample...

Transcript

内反射光谱法,或称衰减全反射红外光谱法,是一种用于获取难以处理样品红外光谱的分析技术,这些样品包括溶解度有限的固体、薄膜、纤维、膏状物和粘合剂。

ATR 基于全反射原理,当一束光以大于临界角的角度从代表高密度介质的晶体进入密度较低的样品介质时,就会发生全反射。

在此过程中,光束穿透晶体后在样品中继续传播一段短距离,产生一束倏逝波。样品在特定波长处吸收这种短寿命的辐射,导致光束衰减,该现象称为衰减全反射。

穿透深度取决于光束波长、晶体和样品的折射率以及光束相对于界面的角度等因素。

ATR 谱包含与常规吸收光谱相同的谱带,但在相对强度上有所不同。

Tags