Direct Colorimetric Determination of Hippuric Acid in Urine

Direct colorimetric determination of hippuric acid in urine.

In 1963 Umberger and Fiorese (1) introduced a colorimetric method for HA,1 based on the color reaction of HA, dissolved in anhydrous pyridine, with BSC. Therefore, for applying their method to determine HA in urine, HA must first be extracted from the urine. We found that HA dissolved in water-pyridine (1:1, by vol) produces a red-orange color when BSC is added at room temperature. The absorpti...

Colorimetric determination of hippuric acid in urine and liver homogenate.

To a dried extract Containing hippuric acid (HA), 1.0 mL of acetic anhydride and 2.0 mL of 0.5% p-dlmethyiamlnobenzaldehyde (DAB) solution In pyridine were added, and the solution was kept at 40 O C for 1 h after thorough mlxing. The absorbance was then determlned at 458 nm agalnst a blank containing acetic anhydride, DAB, and pyridine. This method was in good agreement with Beer’s law within 1...

Colorimetric method for hippuric acid.

FTIPPURIC ACID 1S an important metabolic product normally present in urine in amounts determined by tile ingestion of benzyl-containing foods and medicinals (ii). Because this compound is comparatively inert chemically, identification requires isolation and the determination of physical constants after extensive purification. There has long been need for a reliable and sensitive color reaction ...

The Direct Colorimetric Determination of Urea in Blood and Urine

Methods for the determination of urea in biological fluids have passed through an interesting cycle (cf. Peters and Van Slyke (3) pp. 539-544). The earliest procedures were strictly chemical ones, involving precipitation of the urea as an insoluble mercury complex or decomposition of the urea by means of heat or hypobromite. The use of the highly specific enzyme urease occurring in the jack and...

A modified method for the determination of hippuric acid and free benzoic acid in the urine of cattle.