A Simple and Sensitive Spectrophotometric Method for Iron (III) through a Nucleophilic Coupling of Catechol with 2-Amino-5-methylthiophene-3CarbonitrileAuthor(s): Shyla B, Deepakumari HN and Baburaj A
A simple and sensitive spectrophotometric method is developed for the determination of iron (III) and used for its determination in the laboratory chemicals, lake water samples, green leaves and pharmaceutical samples. The method is based on the catechol oxidation by iron (III) followed by its nucleophilic coupling with 2-amino-5-methylthiophene-3-carbonitrile producing a dye with max 490 in 0.1 M hydrochloric acid. The system is obeying the Beer’s law in the range 0.4 µg ml-1 to 15 µg ml-1 of iron (III). The Molar absorptivity, Sandell sensitivity and correlation coefficient of the system were calculated and found to be 1.404 × 103 mol-1 cm-1, 0.0398 µg cm-2 and 0.9996, respectively. The optimum reaction conditions and other analytical parameters are investigated to enhance the sensitivity of the method. The new method have been applied successfully for the analysis of iron in the laboratory chemicals, lake water samples, green leaves and pharmaceutical samples with good accuracy and precision. The results from the developed method are in good agreement with the official method.