消除显微红外光谱水汽噪音的方法

A Method to Make Water Vapor Peaks Disappear During Measurement of Fourier Transform Infrared Microscopic Spectrum

测量显微红外光谱时,由于光路暴露在开放流通的空气环境中,水汽的吸收峰常常出现在光谱图中而对样品谱造成干扰。本研究在样品单光束谱收集过程中间,通过适时向测试体系通入干燥的氮气或较潮湿的空气来补偿光路中水汽的量,从而达到样品谱和背景谱测量时水汽的平均含量相等,最终消除水汽吸收峰。本方法用于硬脂酸显微红外光谱的测量,观察到水汽噪音由大到小,直至消失的全过程,结果令人满意。

Water vapor peaks(noise) often appear in infrared spectrum.It becomes sometimes serious in the infrared microscopy measurement due to the exposure of the microscope to air.In this study,a novel method to make water vapor noise disappear in the infrared spectrum was proposed.During the measurement of an infrared spectrum,the relative humidity in the infrared optical path was adjusted in time with dry N2 or relatively wet air depending on water vapor content in the system,respectively.By such a way,we can control easily at last that the average amount of water vapor in the sample measurement is equal to that in the background measurement.Therefore,the effect of water vapor on an infrared spectrum can be removed completely.This method was successfully applied to measure the microscopic infrared spectrum of steaic acid.