Design novel optical sensor for determination of bismuth based on immobilization of 4-(4-nitrophenyl)-1-naphthol on a triacetylcellulose membrane

A novel optical sensor has been proposed for sensitive determination of bismuth ion basedon immobilization of 4-(4-nitrophenylazo)-1-naphthol on a triacetylcellulose membrane.Chemical binding of bismuth ions in solution with a 4-(4-nitrophenylazo)-1-naphtholimmobilized on the triacetylcelluse surface could be monitored spectrophotometrically. Theoptode shows excellent response over wide concentration range 0.4-3.6 μg mL-1 bismuth with alimit of detection of 0.14 μg mL-1 bismuth. The influence of factors responsible for the improvedsensitivity of the sensor were studied and identified. The response time of the optode was 30 secfor a stirrer solution. The influence of potential interfering ions on the determination of 0.4 μgmL-1 bismuth was studied. The proposed optode was applied to the determination of bismuth inpharmaceutical formulation samples.