ON-LINE MONITORING OF NITROFURANTOIN IN URINE OF RABBIT BY A FLOW-INJECTION SYSTEM WITH A FIBER-OPTIC CHEMICAL SENSOR

A flow-injection system for monitoring of nitrofurantoin(NFT) in rabbit urinethat makes use of a kind of fiber-optic chemical sensor is presented. The NFT-sensitive optrode wascombined with a membrane onto which was immobilized pyrenebutyric acid(PBA)as a fluoroprobe.The NFT concentration was determined via dynamic quenching of the fluorescence of PBA. Theaverage recovery was 96. 5%～102.9%. The relative standard deviations for within-day andbetween-day were 3.1/～3.7%and 1.6%～3.8%respectively. The calibration curve was linearin the range from 2μg·ml^-1 to 100 μg·ml^-1 with r=0.9983. The detection limit of this method was0.74μg·ml^-1. The urine drug concentration-time course in rabbit after oral administrationconformed to a one compartment open model with a first order absorption phase. Mean T_1/2 value was0.75±0. 14h. The selectivity was affirmed by HPTLC.