Using of 2,7-Dihydroxynaphthalene as a Novel Reagent in Spectrophotometric Assay of Chloramphenicol

Abstract

An indirect spectrophotometric method for the determination of chloramphenicol (CAP) has been suggested. The method is based on the oxidative coupling reaction of reduced chloramphenicol (R-CAP) with 2,7-dihydroxynaphthalene (2,7-DHN) reagent in the presence of potassium dichromate as oxidizing agent to produce brown colored, stable and soluble product. This product showed maximum absorption at 544 nm. Beer's law is obeyed over the range 0.5-7.5.µg.ml-1 of R-CAP and molar absorptivity of 1.069×10 5 l.mol-1 .cm-1 and Sandell's sensitivity index of 0.0030 µg.cm-2 , limit of detection (LOD), limit of quantitation (LOQ), relative error (RE%) and relative standard deviation (RSD%) have been estimated. The method has been successfully applied to the determination of CAP in drug formulations.