Automatic system for the assay of guanidino compounds to assess uremic status and effect of hemodialysis.

An automated HPLC system coupled with fluorometry was established for the sensitive, rapid, and accurate assay of serum guanidines. Naturally fluorescent materials characteristic of the sera of uremic patients (uremic fluorescences) which interfere with the assay were removed simultaneously with deproteinization. Application of this method revealed that the uremic patients who are capable of excreting urine under hemodialysis therapy show low serum guanidinosuccinic acid levels. The interval between hemodialysis sessions in one of these patients was prolonged while monitoring guanidinosuccinic acid level using the present method without any hazardous effect.