1997 Volume 13 Issue 3 Pages 479-483
A highly selective organic phosphates analyzer was developed based on a column-switching technique using a titania (TiO2) precolumn and an anion-exchange analytical column. In the preliminary examination, it was proved that the titania column strongly retains the organic phosphates under acidic conditions while it shows no retention in alkaline eluents. Based on these findings, the organic phosphates were selectively trapped on the titania precolumn in an acidic eluent, transferred to an anion-exchange column by a basic eluent and detected by coloration after a postcolumn phosphomolybdic acid reaction. When 25.0μM each of phospho-amino acids solution was determined (injection volume, 100μl), the relative standard deviations were 2.3-2.8% (n=5). The detection limits (S/N=3) of the phospho-amino acids were ca. 2.0μM as the injected concentration. The present analyzer was successfully applied to the analysis of the phosphorylation products of a heptapeptide (kemptide).
