Increase in HPLC Column length results in?

1. Better resolution between peaks - the length of the columns allows for the individual analytes to separate from each other better than if a shorter column were used
2. Increased chromatographic efficiency (N)- chromatographic efficiency is denoted by the column length (L) divided by the theoretical plate height (H). 
3. Practicality-wise, longer analytical runs, i.e. longer waiting periods to obtain peaks

Delay in emergence of the peaks in chromatogram.

Some times a better separation

Spreading of the Peaks and increasing Tailing Factor (TF) and Reducing the resolution of the peaks

But, in practice, it hardly depend on the analyte, the method of analysis, the nature of mobile phases, and the type of the LC Column

better resolution and longer run time.

1. inrease in resolution

2. improved efficiency

3. increase in retention time.

increase number of theortical plate so better separetion

Increase RT

Better reselution

Better seperation

1- Better seperation between peaks.

2- Better resolution.

3- Increase retainion time which leads to increasing pnjection time, causing more time, and mobile phase to be consumed.

4- Lead to increase pressure due to force needed for flowing mobile phase through the column, where The Pressure (P) = Force (F) / Area (A)

retention time increases

better seperation  better resolution

Increase retention time and analysis time compared to a shorter column.

1) better resolution

2) longer R.T

3) Better efficiency

lating appearance of componenet(increase Retention time)