Question

how long can we store amino acid solution mixture

Answer 1

We used to store stock 100mM Fmoc-aa in DMF at 4ºC for peptide synthesis and store peptides in solution at 4ºC. Your 100mM Phe and PP solutions in dH2O should be stable at 4ºC and room temperature. I would make the 550mM Tyr in HCl fresh each time.