Determination of urobilinogen in urine
From WikiLectures
As with bilirubin, the principle of azocoupling reaction with a stable diazonium salt (eg 4-methoxybenzenediazonium tetrafluoroborate) is used to determine urobilinogen in urine . The indication zone turns pink to red in the presence of urobilinogen. The faint pink color still corresponds to the physiological excretion of urobilinogen. In the presence of bilirubin , the color is yellow, which turns green to blue after 1 minute.
Some heterocyclic nitrogenous substances produced by bacteria in urinary tract infections can cause false positives . High concentrations of ascorbate can cause false negatives .
