[Determination of urobilinoide concentration in the urine. New rapid method for clinical determination of urinary-urobilinoids using the Ehrlich-reaction].

A rapid method for quantitative determination of concentration of urobilinoids of fresh urine was developed. The method is based upon extraction of urinary urobilinoids using a mixture of acetic acid and ether and followed by the extraction of the ethereal phase with Ehrlich reagent and a solution of sodium acetate. Readings of absorbance from the absorption band of reaction products from urobilinoids and Ehrlich reagent are done. Performance of the rapid method: 2 ml urine + 10 ml ether + 2 ml acetic acid were thoroughly mixed for about 15 seconds. The ethereal extract was shaken after addition of 12 ml Ehrlich-reagent for 1 minute and 15 ml half-saturated sodium acetate solution were added. 0-3 minutes afterwards reading of absorption at 560 nm respectively filter Hg 578 nm. Photometer:mg/dl=29 X A578 nm, 1 cm -0,4. Spectrophotometer:mg/dl urobilinoids=13,7 X A560 nm X 1/d -0,22 (d=optical pathway). Photometrical determination of concentration of urobilinoid can also be done using table 1. Accuracy, reproducibility and specificity are fully satisfying for clinical use of the method.