[Possibilities of stabilization of bilirubin in the bile during the preparation of reference materials].

Quaternary bis-ammonium salt No. 81 in concentrations of 0.2 to 1.62 mmoles/liter stabilizes the bile and preserves the bilirubin content unchanged in it for 120 days of storage in the dark at room temperature. In order to prepare the reference sample, 0.04 mmoles of this chemical is dissolved in 100 ml of the first-fifth portions of the bile, mixed, disposed in small flasks, and stored in the dark at 18-20 degrees C. This reference material is fit for quality control of bilirubin measurements in the bile by the Van den Berg test for 120 days.