Correlation of a Colorimetric and a HPLC Method for the Determination of Serum Hippuric Acid Concentrations in Uremia

Abstract

Hippuric acid has been recognized as a potential marker of uremic toxicity in chronic renal failure. However, in most studies, serum hippuric acid concentrations have been determined by sophisticated methods, such as high-performance liquid chromatography. The present study was undertaken to evaluate whether the less complicated colorimetric determination method could replace such methods. Based on 21 different samples, the results obtained by both methods appeared to be correlated to each other in a highly significant way (total hippuric acid: r = 0.99, p < 0.001; free hippuric acid; r = 1.00, p < 0.001). Mean total and free hippuric acid concentrations and mean percent protein binding, obtained with both determination methods, were also identical. It is concluded that both the colorimetric method and high-performance liquid chromatography are equally reliable for the study of the concentration of hippuric acid in uremic serum and of its importance as a marker of the clinical and biochemical epiphenomena of uremic toxicity.

Mass Spectrometry Imaging of Kidney Tissue Sections of Rat Subjected to Unilateral Ureteral Obstruction

“…6c and Figure S3u ). Hippuric acid has been recognized as a potential marker of uremic toxicity in chronic renal failure 22 .…”

A Study of Deproteinization Methods for Subsequent Serum Analysis with Capillary Electrophoresis

“…Acid precipitation/acetonitrile extraction (7,10): Serum (0.500 ml), HCl (0.020 ml, 6.0 M), glacial acetic acid (0.020 ml), NaCl (150 mg), and ACN (2.500 ml) were combined in a test tube and Vortex-mixed for 1 min. The supernatant (1.00 ml) was blown with nitrogen until the solution was reduced to 0.500 ml.…”

Biochemical Definition of the Uremic Syndrome and Possible Therapeutic Implications

“…We conclude that urea is only partially representative as a marker of the dialytic concentration changes of other retention compounds and that alternative markers such as hippurate, measured either by colorimetry or by HPLC peak height analysis (14), should be considered. This is especially im-portant in view of our findings of the interference of several solutes with biological systems, many of which have a different intradialytic behavior than urea.…”