What is the purpose of retention time in chromatography?

Some points on purpose of retention time in chromatography are:

• Retention time reproducibility allows chromatographic results from repeated runs to be compared under the same method conditions.
• Consistent retention times indicate stable mobile phase composition, flow rate, and column temperature.
• Reproducible retention time values support reliable comparison of samples analyzed at different times.

Also check it out importance of retention time in chromatography to learn more about it.