DIRECT QUANTITATIVE-DETERMINATION OF OPTICALLY-ACTIVE ABSORBING DRUGSIN HUMAN URINE BY CIRCULAR-DICHROISM - SIMULTANEOUS DIRECT DETERMINATION OF BETA-LACTAM ANTIBIOTICS AND PROTEINS

Over 200 urine samples from 61 subjects were analyzed by circular dich roism spectroscopy. The results proved that this technique can be appl ied to the direct determination of optically active absorbing drugs in urine of subjects under multiple drug administration, independently o f the presence of proteins, which can simultaneously be determined. A list of noninterfering drugs is included. The validity of the present method was confirmed by analysis of variance, the beta-lactam antibiot ics ampicillin, cefoxitin, and cephalexin being chosen as model drugs and human albumin as the analytical standard for protein determination . The results demonstrated that the proposed method is accurate and pr ecise, the correlation coefficients being higher than 0.9996. A circul ar dichroism and HPLC data comparison was successfully performed. The principal advantages of this method are simplicity, quickness, and eco nomy, no derivatization or chromatographic separation steps being need ed.