High-performance liquid chromatographic analysis of guanidino compounds using ninhydrin reagent. II. Guanidino compounds in blood of patients on haemodialysis therapy.

An automated high-performance liquid chromatographic method using alkali-ninhydrin reagent for the post-column derivatization of guanidines has been developed. This procedure was applied to measurements made before and after haemodialysis. Among the guanidino compounds found in human blood, methylguanidine showed the lowest removal rate. The removal rate of guanidinosuccinic acid correlated with the plasma alpha 1-globulin fraction. The removal rate of each guanidino compound decreased with the period of dialysis.