Evaluation of a carbon paste electrode modified with Strontium substituted bismuth and titanium oxide nanoparticles in the toxic metal chromium (VI) determination potentiometric method

Strontium substituted bismuth and titanium oxide nanoparticles with aurivillius morphology synthesized by chemical co-precipitation method and were characterized using XRD. The nanopartcles were used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. A procedure for the determination of chromium is described based on pre-concentration of the dichromate anion at a carbon paste electrode modified. A novel potentiometric Cr ⁶⁺ carbon paste electrode incorporating Strontium substituted bismuth and titanium oxide nanoparticles (SSBTO). Ina acetate buffer solution of pH 5, the sensor displays a rapid and linear response for Cr ⁶⁺ over the concentration range 1.0×10-5 to 1.0×10-1mol L⁻¹ M with an anionic slope of 54.8±0.2 mV decade ’ and a detection limit of the order of0.002/μg ml ‘. The sensor is used for determination of Cr ⁶⁺ by direct monitoring of Cr ⁶⁺.The average recoveries of Cr ⁶⁺ at concentration levels of 0.5∼40 pg/ml ’is 98.3. The electrode has a short response time (<6s) and can be used for at least twenty days without any considerable divergence in potentials and the working pH range was 4.5–6.5. The proposed electrode was successfully used as an indicator for potentiometric determination of Cr ⁶⁺ in water sample.