A versatile vanadium(III)-based chemiluminescence protocol for nitric oxide metabolite quantification and NO release kinetics.

Nitric oxide (NO) is a central mediator of vascular, neurological, and immune functions, and its dysregulation is implicated in a broad spectrum of diseases. Despite its significance, direct measurement of NO in human samples is limited by its transient nature and rapid conversion to nitrate and nitrite. Accurate, rapid, and accessible quantification of these NO metabolites in clinical and research settings remains a key need. We present a vanadium(III)-based chemiluminescence protocol for the reliable detection of nitrate and nitrite in human biological fluids, including serum, urine, and cerebrospinal fluid. In addition, this method supports headspace gas analysis, enabling precise determination of nitric oxide release kinetics and half-life from NO-producing compounds. This approach offers a cost-effective and scalable solution suitable for routine analysis in both diagnostic and research laboratories.