A novel ion-selective sensor for procaine hydrochloride based on a piezoelectric quartz crystal coated with a procaine tetraphenylborate PVC membrane

A novel ion-selective sensor for procaine hydrochloride has been proposed a nd applied successfully to analysis of pharmaceutical preparations. The sen sor is based on modification of the Ag-electrode of an AT-cut piezoelectric quartz crystal with a PVC membrane containing procaine tetraphenylborate. A linear relation between the logarithm of the response frequency and the l ogarithm of the procaine hydrochloride concentration was found experimental ly and could be explained by combination of a modified Sauerbrey equation a nd the Freundlich isotherm. The detection range was from 8.3 x 10(-8) to 5. 0 x 10(-3) M with a detection limit of 8.3 x 10(-8) M. The selectivity of t he sensor and the influence of experimental parameters such as solution pH and detection time were investigated.