A new peroxyoxalate chemiluminescence of bis (2, 4-dinitrophenyl) oxalate (DNPO) using pyronin Y as the fluorophore and its application to the flow-based determination of cysteamine

Peroxyoxalate chemiluminescence (POCL) systems have received great attention due to their high quantum yield and the ability to emit a wide-range colors by the utilizing different fluorophores. In this research, Pyronin Y (PY) was first introduced as the fluorophore for a POCL system. Our results indicated that the reaction of (2, 4-dinitroophenyl) oxalate (DNPO) with hydrogen peroxide (H₂O₂) catalyzed by sodium salicylate (SS) could transfer energy to Pyronin Y via the formation of the dioxetanedione intermediate and emit orange-red light. The relationships between chemiluminescence (CL) intensity and the concentrations of DNPO, fluorophore, H₂O₂, and the catalyst were investigated. Moreover, the analytical utilization of the new CL system was evaluated by detecting a drug, cysteamine, in pharmaceuticals. A linear working range for cysteamine concentrations from 3 × 10 ^-8 to 7.5 × 10 ^-6 molL^-1 (r > 0.9907, n = 5) and a detection limit of 7.8 × 10^-9 molL^-1 were obtained, respectively. The relative standard deviation for five repetitive determinations was less than 3.8 %, with estimated recoveries of 100.1 % and 103.4 %. This method shows high sensitivity for the assay of cysteamine.