Flow injection determination of isoniazid using N-bromosuccinimide- and N-chlorosuccinimide-luminol chemiluminescence systems

A chemiluminescent method for the determination of isoniazid is described. Method is based on the chemiluminescence (CL) generated during the oxidation of luminol by N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) in alkaline medium. It was found that the isoniazid could greatly enhance this CL intensity when present in the luminol solution. Based on this observation, a new flow-injection CL method for the determination of isoniazid is proposed in this paper. The detection limits were 4 and 3 ng ml −1 isoniazid for the NBS- and NCS-luminol CL systems, respectively. The relative CL intensity was linear with the isoniazid concentration in the range of 8–600 and 600–5000 ng ml −1 for the NBS-luminol CL system, and 6–200 and 200–2000 ng ml −1 for the NCS-luminol CL system. The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official method and demonstrated good accuracy and precision.