Types of chromatographic column
If the chromatographic column is classified by functions, there are separation column and adsorption column. If the chromatographic column is classified by polarity, there are polar column and non-polar column.
What makes the sample separated based on stationary phase?
Mainly on volatility, polarity, special effect, with or without hydrion.
Several methods of chromatographic separation
1. Flush methodUse carrier gas to make mobile phase sample, inject quantitatively in short time.2. Replacement methodThe sample enters into column, then, replace the ouput column with a replacement agent.3. Head methodThe sample enters into chromatographic column continuously as mobile phase.
Required conditions for increasing chromatographic resolution of column
1. Lower pressures at input port and output port;2. Smaller volume;3. Lower column temperature (column temperature increased 30 degrees, the retention time reduced by half)4. Smaller column diameter;5. Smaller sample quantity;6. Carrier gas with large molecular weight (small spreading);7. Evenly packing ...
Types of gas chromatography detectors
1. Thermal conductivity detector (TCD)2. Flame ionization detector (FID)3. Helium ionization detector (HID)4. Electron capture detector (ECD)5. Flame photometric detector (FPD)6. Density balance detector (DBD)7. Cross-sectional area ionization detector (CID)
Common adsorbents in actual use
The following adsorbents are commonly used for gas chromatograph column: active carbon, molecular seive, active alumina, graphitized carbon, bentonite and porous polymer bead etc.
How long is the service life of high temperature capillary column
The service life of capillary column depends on its own quality and using conditions, including using temperature, sample condition and sample injection quantity etc. If the sample is clean, chromatographic column is not polluted and the capillary column applied within its using temperature range, the ...
General introduction to polychlorinated biphenyls (PCBs)
Polychlorinated biphenyls (PCBs) which is a kind of chlorinated aromatic hydrocarbons formed by catalyzed and chlorinated under the high temperature conditon. Its raw material is biphenyls. Because of its good flame resistance, low conductivity, anti-pyrolysis and chemical stability, it were widely used ...
FURAN analysis on transformer oil
FURAN analysis on transformer oil indicates the degree of degradation of the transformer paper insulation. This is usually done in transformers aging above 15 years. FURAN indicates the compounds of carbon and hydrogen. When the FURAN count is above 2500ppb, it means the transformer is about to fail. ...
Auxiliary techniques help gas chromatography improve the probability of compound
Gas chromatography is an excellent technique for the separation of the components of a mixture and for their subsequent quantitation. However, it is not easy to determine the qualitative nature of the separated components. A number of auxiliary techniques have been employed to improve the probability ...