very good post, i have a correction here, at 14:10 you said that you can separate RNA and DNA with size exclusion chromatography which is not true RNA and DNA can be separated by gel electrophoresis :)
Before commenting you should know what you are telling. By the way in GC, separation is not based on boiling point. It is based on affinity of samples towards stationary phase and mobile phase( career Gas)
In isocratic separations, analyte retention time can be normalised to retention factor, k, which allows a direct comparison between columns with different dimensions. This is possible due to the constant mobile phase composition used in isocratic methods.Gradient retention factor, k*, also known as average k, can be used to describe the chromatographic conditions. k* requires a range of 2 < k* < 10, similar to that of retention factor, k. If k* is below 2, there is potentially insufficient interaction between the analyte and the stationary phase, whilst above 10, the run times can be excessive, which can decrease laboratory productivity and increase solvent consumption
Column back pressure is back pressure due to Column. As mobile phase passes through Column containing stationary phase of fine particle (3 micron or 5 micron), the pressure is generated.
