Determination of procaine hydrochloride using flow injection inhibitory chemiluminescence

A new flow injection chemiluminescent method has been developed for the determination of procaine hydrochloride, based on the inhibition of the chemiluminescence reaction of luminol-hydrogen peroxide by procaine hydrochloride. The influence of several surfactants and beta-cyclodextrin on the chemiluminescence intensity were studied. It was found that beta-cyclodextrin enhanced the decrease in chemiluminescence intensity. The method is simple, convenient and sensitive, with a detection limit (3 sigma) of 0.08 micro g/mL. The decreased chemiluminescence intensity is linear, with the concentration of procaine hydrochloride in the range 0.2-100.0 micro g/mL and 100.0-400.0 micro g/mL. The relative standard deviation for 10 repeated measurements were 4.5% and 3.4% for 1.0 and 20.0 micro g/mL procaine hydrochloride, respectively. The method has been successfully applied to the determination of procaine hydrochloride in injection solutions of this drug.