Sensitive determination of ultra-trace nitric oxide in blood using derivatization-polymer monolith microextraction coupled with reversed-phase high-performance liquid chromatography

Nitric oxide (NO) plays a very important role in human blood system. In this work, a novel approach has been developed for the quantitation of ultra-trace NO derivatized with 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s- indacene (DAMBO) using a polymer monolith microextraction (PMME) with a poly(methacrylic acid-ethylene glycol dimethacrylate) (MAA-EGDMA) monolith in conjunction with high-performance liquid chromatography (HPLC). Both derivatization and PMME conditions have been optimized in detail. The detection limit of derivatized NO was 2 × 10−12 mol L−1 (signal to noise = 3) and linear range was 9 × 10−11–4.5 × 10−8 mol L−1. The proposed DAMBO-based derivatization-PMME–HPLC-fluorescence detection method has been successfully applied for the determination of NO in 10 μL blood samples of healthy persons and patients suffering from ischemic cardio-cerebrovascular diseases with recoveries varying from 87.40 to 91.60%.