Chromatography ‘’ a separation technique based on the different affinities of the components of a mixture to two immiscible phases, One phase is stationary, the other mobile’’

Or                                                                                                                                           

‘’Differential migration of compounds according to their solubility and affinities in different immiscible phases, One phase is stationary, the other mobile ’

1. Classification of Chromatography(According to Mobile Phases):

The mobile phase of chromatographic system can be gas, a liquid, or a supercritical fluid. The stationary phase is either a solid or a liquid. These options all to convenient classification of the chromatographic process as listed in table.

 Table 1-1.Classification of chromatography according to the aggregation state of the mobile phase.

Mobile Phase                                            Stationary Phase             Abbreviation

Gas                                                          Solid                                            GSC

Gas                                                        Liquid                                            GLC, GC

Liquid                                                    Solid                                              LSC,LC

Liquid                                                     Solid                                             LLC

Supercritical fluid                                Liquid(solid)                                 SFC

The above chromatography must be selected depending on the chemical nature (one of these, separation principles) of the components of a mixture.

1.1.  Gas chromatography- Gas chromatography is a technique by which we can analyze volatile, semi volatile compounds. In gas chromatography we have used mobile phase in the farm of gases and stationary means column itself contain liquid.

Working Phenomenon of GC:  Specifically gas-liquid chromatography - involves a sample being vaporized (in Injector port) and injected onto the head of the chromatographic column. The sample is transported through the column by the flow of inert, gaseous mobile phase. The column itself contains a liquid stationary phase which is adsorbed onto the surface of an inert solid. The thermal programming when increased and reached to analyte boiling point then the analyte come in to the flow of mobile phase and reach to the detector. Detector detected that analyte and send to signal to recorder (dedicated software for particular instrument)

Figure: 1-1 Black diagram of Gas chromatography

1.2.  Liquid Chromatography: The mobile phase used in the form of Liquid and stationary phase used in the form of Solid of super fluids.

EXAMPLE- HPLC

                                       

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