Bandspreading
The dilution of the chromatographic band as it moves down the column. The peak is injected as a slug, and, if not for the process of band broadening, each separated component would elute as a narrow slug of pure compound. The measure of band broadening is band width, tw, or more correctly, the number of theoretical plates in the column, N.
Usually after like 4-5 days…but it is rare that I have anything that lasts that long with zero imnmeveropts. 2 weeks is a long time to be suffering! I hope you get to a doctor soon and they give you some relief.