The effect of phytic acid on the resolution of peptides and proteins in capillary electrophoresis.

Studies are reported on the effect of the sodium salt of phytic acid on the resolution of peptides and proteins. Improved separation in the case of peptides is shown to be due to ion-ion pairing interactions between the positively charged peptides and the phytic acid polyanionic species. The improved peak shapes related to the proteins can be interpreted in terms of the sample preconcentration due to injection of analytes from a water medium to one of high ionic strength.