Question

ORGANIC CHEMISTRY : GAS CHROMATOGRAPHY

the retention time of a particular compound depends on the conditions under which the chromatograph is obtained. therefore, it is important to record those conditions onto the chchromatogram.what four conditions set for the gas chromatography apparatus that you need to record? .also if you are trying to seperate an aldehyde from a ketone,what typ eof stationary phase is likely to work? a polar o rnonpolar stationary phase? explain.

Answer 1

There are many conditions onto which the retention time depends

a) Boiling point: A high boiling point substance will have high retention time as compared to low boiling point substance

b) Temperature: A high temperature of column leads to low retention time. It may cause poor separation. So we keep low temperature of column

c) Column length: high retentional time is govern by longer column

d) Gas flow rate: higher the flow rate lower the retention time poor the separation

2) we use polar stationary phase like Styrene-DVB for separation of aldehydes from ketones.