Well -- if you needed a protocol for doing urine peptidomics, all the way down to standardizing everything to the urine creatinine levels (90umol, if you were wondering) and wanted some WTFourier level proof that this is a good use of your time, may I present:
1) I didn't know urine peptidomics was a thing
2) This group reduces and alkylate their endogenous peptides. I'm unclear on whether or not I think that is a good idea, but considering how this paper develops downstream, I'm just going to shut up and do exactly what they did.
Discovery was all done on a Q Exactive coupled to a
Validation? Well -- they tripled the speed of the mass spec and increased the speed of their separation by over 7 orders of magnitude with an EvoSep coupled to an HF-X. (I guess the EvoSep isn't 1e7 times faster, but is sure feels like the slEasyNLC is taking the length of a human lifetime to load a single sample.
All the data is up on ProteomeXchange and Panorama, but you should read this great paper and find the links yourself!