布鲁克红外光谱培训.ppt

定性分析： 1. 鉴定未知物 2. 核对已知物 定量分析 光谱评价 未知物的鉴定 a) 通过光谱解析推出分子结构 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 Wavenumber / cm-1 40 60 80 100 Transmission [%] 20 不同有几类分子的红外吸收 烷烃 烯烃 芳香烃 内酯 卤化物 羧酸盐 酸酐 b.) 与标准谱库比较 e.g. by using OPUS/Search 未知物的鉴定 identical material = identical IR spectrum - What you have: sample - What you need: reference library - What you do: comparison with reference library - What you get: identification 验证已知物 2.) Calculate average spectrum threshold values 3.) Library structure validation ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 1.) Measure reference sample Wavenumber / cm-1 Absorbance Wavenumber / cm-1 Absorbance Reference library structure Identified sample: material X 1.) Measure new samples 2.) Compare with library Identifying new samples 3.) Identify material - What you have: sample - What you need: calibration set - What you do: comparison with calibration set - What you get: concentration value There are two different forms of calibration: Univariate calibration (OPUS) - Correlates just one piece of spectral information (e.g. peak height or peak area) with the reference values of the calibration set. Multivariate calibration (OPUS/QUANT) - Correlates considerably more spectral information - higher degree of precision - reduced chance of error OPUS/QUANT uses the Partial Least Squares (PLS) Method. X Analysis 1 2 3 4 Absorbance Concentration X 1 3 2 4 Absorbance Wavelength Calibration Quantitative evaluation of spectra 2.) Build calibration set (Quant Method) 3.) Validate calibration set 1.) Measure calibration spectra Wavenumber / cm-1 Absorbance Setup of a Quant Method 1 2 3 4 Absorbance Concentration Concentration:58 vol. % 1.) Measure sample 2.) Compare with calibration set Determine quantitative results (e.g. concentration values) 3.) Result FT-IR measurements Enter sample name Start the background and sample measurement Sampling bandwidth in interferogram domain 傅立叶红外光谱介绍 傅立叶红外光谱介绍 电磁波