CHROMATOGRAPHY Electrochromatography Gel Electrophoresis Principle Electrophoresis is a

CHROMATOGRAPHY

Electrochromatography (Gel Electrophoresis) Principle -Electrophoresis, is a type of planar chromatography and is defined as: The process where by charged particles can be separated by selective migration in an electric field. -Electrovalent ions of different signs and charges will move at different speedsto opposite electrodes The driving forces are the electric forces of attraction between the electric field and the charged molecules and are proportional to mass/charge (m/e) ratio. Uncharged molecules will not respond to the field effect and will not move.

Gas Liquid Chromatography

Qualitative known Rtvalues under standard conditions mixture of hydrocarbons eg petrol mixture of alcohols air But Must be able to be vaporised up to about 300 o. C Must not decompose Quantitative Calibration graph of a series of standards of known concentration plotting area under peak vs concentration

Uses of Gas chromatography I- Qualitative Analysis (Identification) through: a- Retention time - It is the time between the emergence of the air peak and that of the compound. b- Addition of the suspected substance (spiking) - Comparison between gaschromatogram obtained before and after addition of suspected substance If peak enhanced +Ve -Ve