RP column for tryptic peptides

[GCFun]

Hi everyone,
I want to analyze a tryptic peptide solution after extraction (and digestion) from a coomassie stained gel. I have the need to use a HPLC coupled to an ESI (NOT nanoESI) and I am looking for a good solution which allow to achieve good sensitivity using a uL/min flow (NOT nL/min). I found two C18 columns, both 2.1 mm; 150 mm; but differing for particle size 3 or 5 um. Do you think one of them is ok for me? What flow should I use?

Thanks!!!

[tom jupille]

Unless you want to re-invent the wheel, look for application notes from your vendors of choice that are close to what you want to do.

Assuming two columns from the same vendor with the same stationary phase "name", the particle size will affect the back pressure (smaller = higher) and the width of the peaks (smaller = narrower). If you are talking about two different stationary phases (even if both are C18), then stationary phase chemistry will have a much bigger impact that will particle size.