西北师范大学：《仪器分析》课程教学资源（PPT课件）Chapter 02 气相色谱法 Gas Chromatography（GC）

Chapter 2 Gas Chromatography(GC) §2-1 Summary ●Chromatographic separation technique(色谱分离）: A separation technique based on partition of 2 or more substances in a mixture in two phases(色谱法、色层法、 层析法,chromatographer） ● Chromatographic analysis（色谱分析）: Chromatographic separation applied on analytical chemistry Advantages: High separation efficiency, high detection efficiency, fast analytical velocity GC

Chapter 2 Gas Chromatography(GC) §2-1 Summary ●Chromatographic separation technique(色谱分离）: A separation technique based on partition of 2 or more substances in a mixture in two phases(色谱法、色层法、 层析法,chromatographer） ● Chromatographic analysis（色谱分析）: Chromatographic separation applied on analytical chemistry Advantages: High separation efficiency, high detection efficiency, fast analytical velocity GC

●Mobile phase & Stationary phase（流动相与固定相): Chromatographic separation involving partition of different species in a mixture in two phases, among which one phase (solid or liquid) does not move (stationary phase) , the other phase (gas or liquid) takes the sample mixture to pass through the stationary phase packed in the column( mobile phase) Separations are affected due to the differences of substances’ affinities for a mobile phase and a stationary phase(分离原理）. GC

●Mobile phase & Stationary phase（流动相与固定相): Chromatographic separation involving partition of different species in a mixture in two phases, among which one phase (solid or liquid) does not move (stationary phase) , the other phase (gas or liquid) takes the sample mixture to pass through the stationary phase packed in the column( mobile phase) Separations are affected due to the differences of substances’ affinities for a mobile phase and a stationary phase(分离原理）. GC

(a) Sample Mobile phase A+B Packed column A B Detector 2

Gas supply Flow controller Oven Column To waste Detector Flow meter (In one of these positions) Injection system Amplifier Integrator Recorder GC

Gas supply Flow controller Oven Column To waste Detector Flow meter (In one of these positions) Injection system Amplifier Integrator Recorder GC

皂膜流量计 转字流量计 调整仪，标 准仪 Setup of Gas Chromatograph GC

皂膜流量计 转字流量计 调整仪，标 准仪 Setup of Gas Chromatograph GC

inert gases wothout interaction with analytes or stationary phase 管状的 Thermal conductivity detector Electron capture detector , IR, FPD Flame photometric detector Hydrogen flame ionization detector

inert gases wothout interaction with analytes or stationary phase 管状的 Thermal conductivity detector Electron capture detector , IR, FPD Flame photometric detector Hydrogen flame ionization detector

Chromatogram of xylene isomers on a polar column GC

Chromatogram of xylene isomers on a polar column GC

Y

Y

GC 0 12 4 Peak width at a half height Peak width at peak base Adjusted retention time Rotention time Dead time Air peak 1/2 0.607h h 2s Y1/2 Y t'R tR tM Injection t Response signal Chromatogram Time(arbitrary units)

GC 0 12 4 Peak width at a half height Peak width at peak base Adjusted retention time Rotention time Dead time Air peak 1/2 0.607h h 2s Y1/2 Y t'R tR tM Injection t Response signal Chromatogram Time(arbitrary units)

Nomenclature of Chromatographic separation ●Chromatographic Curve & Chromatogram The chart of output detector response (concentration) versus time The protuberance in the curve is called chromatographic peak 如果进样量很小，浓度很低，在吸附等温线（气 固吸附色谱）或分配等温线（气液分配色谱）的 线性范围内，则色谱峰是对称的

Nomenclature of Chromatographic separation ●Chromatographic Curve & Chromatogram The chart of output detector response (concentration) versus time The protuberance in the curve is called chromatographic peak 如果进样量很小，浓度很低，在吸附等温线（气 固吸附色谱）或分配等温线（气液分配色谱）的 线性范围内，则色谱峰是对称的