BISMUTH IN HUMAN SERUM - REFERENCE INTERVAL AND CONCENTRATIONS AFTER INTAKE OF A THERAPEUTIC DOSE OF COLLOIDAL BISMUTH SUBCITRATE

A sensitive method for the determination of the bismuth concentration in human serum is described. Analyses were carried out by inductively coupled plasma-mass spectrometry (ICP-MS), after a simple dilution of the samples with nitric acid. The detection limit of the applied metho d is 0.007 mug/l whereas relative standard deviations varied from 5.7 to 13.6%. Determination of reference values in human serum of healthy adults gave a range from < 0.007 to 0.067 mug/l (19 persons). Bismuth concentrations in serum were also measured before, during and after th e intake of therapeutic doses of colloidal bismuth subcitrate (CBS). A bout 1.5-2 h after the intake of one tablet of CBS, the bismuth concen tration in serum was found to have increased 51-1483 times (two appare ntly healthy volunteers and six hospitalized patients), showing that t he serum bismuth concentrations can increase by several orders of magn itude during the intake of CBS. During the intake of four tablets of C BS per day by two apparently healthy volunteers, bismuth concentration s in serum after an overnight fast were found to be, respectively, 5.5 6 and 8.1 mug/l on day 15 and 4.28 and 13.6 mug/l on day 29. After sto pping the therapy, the concentration of bismuth in serum slowly return ed towards normal over a period of months.