A poly (vinyl chloride) matrix membrane sensors for selective determination of camylofin (CY) in pharmaceutical formulations were developed based on the use of dibenzo-18crown-6 (DB18C6) as a neutral carrier and ion-association complex ([CY]2[PM])of (CY) cation with phosphomolybdate anion (PM). Subsequently, these electroactive materials were dispersed in dioctyl sebacate (DOS) as solvent mediator designed and can be easily used in flow injection system. Under static mode of operation, the sensors revealed a near Nernstain response over a wide CY+ concentration range 8.5x 10-6 and 5 x 10-6 to 1.0 x 10-2 mol L-1 with a detection limit of 6.0x10-6 and 2.5x10-6 mol L -1 , respectively. In flow injection potentiometry, excellent reproducibility (RSD %±0.7%), fast response, high sensitivity with a nearNernstian 53.9±1.1 and 40.2±0.8 mV decade-1 , linear range 1.0x10-4 -1.0x10-2 mol L-1 , detection limit 16.4±0.3 and 5.9±0.3 μg mL-1 , high sampling rate (20-22 and 40-45 sample h-1 ) and stable baseline was observed in the presence of 0.05 mol L-1 citrate buffer, pH 4.5 as a carrier for ([CY]2[PM] and (DB18C6) membrane based sensors, respectively. The utility of the sensors was tested for field monitoring of CY+ in different pharmaceutical formulations collected from the local market.
Key words: camylofin; smooth muscle relaxant; potentiometric sensor; flow injection analysis.
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