Design and characteristics of tin (II) optode based on immobilization of dithizone on a triacetylcellulose membrane and its application in canned foods

Abstract  

The characterization of an optical sensor membrane is described for the determination of tin (II) based on the immobilization of dithizone on a triacetylcellulose membrane. The membrane responds to tin (II) ions by changing color reversibly from green to red in buffer solution at pH 6 and wavelength 611 nm. This optode has a linear range of 0.3–6.33 μg cm⁻³ (2.52–53.32 μmol dm⁻³) of Sn²⁺ ions with a limit of detection of 0.15 μg cm⁻³ (1.26 μmol dm⁻³). The response time of the optode was about 8–10 min depending on the concentration of Sn²⁺ ions. The selectivity of the optode to tin (II) ions at pH 6 was good. The sensor can be readily regenerated by exposure with EDTA solution. The color is fully reversible, and the optical sensor could be fully regenerated. Experimental results showed that the optode could be used as an effective tool in analyzing the tin content in canned foods.