AAA Sample Preparation

[JimH]

I am currently working with several small peptides that I am getting inconsistent AAA results for, and I suspect this is due to solubility difficulties. I have been using water and up to 50% acetonitrile to solubilize my dry peptide for dilution and evaporation in preparation for hydrolysis. Can anyone suggest other suitable solvents to better solubilize acidic and hydrophobic sequences, which will not interfere with my AAA results? I am using the Waters AccQ-Tag method with an Eldex H/D Workstation for the hydrolysis step.

Regards,
Jim

[Mark Tracy]

Have you tried 0.01 M HCl?

[JimH]

I tried 0.01M HCl as well as up to 0.4% TFA with no success on some of the more difficult sequences. My best results lately have come with the use of 100% DMSO with increased evaporation times.