Modeling and Optimizing of Effective Factors on Kinetic Spectrophotometric Determination of Vitamin B12

A new, accurate, sensitive, and reliable kinetic spectrophotometric method for the determination of vitamin B-12 in biological samples and pharmaceutical formulations has been developed. A central composite design (CCD) of the response surface methodology was used in our research to investigate the effect of reaction time and temperature and the concentration of reagents including orange G, bromate, and sulfuric acid on the assay of vitamin B-12. Vitamin B-12 shows a strong inhibitory effect on the oxidation of orange G by bromate in acidic media. The wide linear dynamic range, low detection limit, and short time analysis introduce the proposed method as a new strategy for the determination of vitamin B-12 in biological and pharmaceutical samples. Also, linear polynomial mathematical models were obtained for the determination of vitamin B-12. Under optimum experimental conditions, the calibration curve was linear over the range 1.0-200.0 mu g/mL. The limit of detection was 0.56 mu g/mL. Statistical comparison of the results with the reference methods shows excellent agreement and indicates no significant difference in accuracy and precision.

Automated summary

A new kinetic spectrophotometric method has been developed for the determination of vitamin B-12 in biological samples and pharmaceutical formulations, showing wide linear dynamic range, low detection limit, and short analysis time. Mathematical models were obtained for the determination of vitamin B-12 under optimal conditions, with excellent agreement with reference methods in terms of accuracy and precision.