Simple Spectrophotometric Method for Determination of Iron(III) Content

Abstract

Introduction: The objective of our work was therefore to develop a simple spectrophotometric and cost-effective method for determination of iron(III) using commercial doxycycline capsule as a reagent.The developed method was applied for analysis iron(III) level in fruit juice samples which was compared the resulting with flame atomic absorption spectrophotometric method. Materials and methods: This study was based on the complex formed between iron(III) solution and doxycycline reagent solution from commercial doxycycline capsule characterize by an absorption maximum at 435 nm.The experimental conditions were optimized by means of the univariate method. The sample preparation of fruit juice were digested by heating under reflux for 1.5 hrs and were measured iron(III) level. Results: The linear calibration curve was constructed using iron(III) standard which was contained iron(III) standard solution in rage of 0.3 -10.0 µg mL^-1. Over the above concentrations range, linear regression of the absorbance of iron(III) (y) and concentration of iron(III) (x) expressed the equation y = 0.0968x + 0.0336 (r²=0.9948, n=3). The relative standard deviation (RSD) of proposed method calculate from 7 replicate of iron(III) 3.0 and 7.0 µg mL^-1 were found to be less than 0.0003 % of each. The percentage recoveries of iron(III) 3.00 and 7.00 µg mL^-1 (n=7) were found to be 97.86 % and 103.96 %, respectively. Effect of some possible interfering ions (Na⁺, K⁺, Zn²⁺, Mg²⁺, Ca²⁺, Al³⁺, Cu²⁺, Mn²⁺and Fe²⁺) on the determination of iron(III) were investigated using present method. Almost of cations tested caused interference <±3 % for determining the analyte of interest. Conclusion: The iron(III) level in fruit juice samples obtained from the proposed spectrophotometric method and flame atomic absorption spectrophotometric method were in accordance, as compared by the t-test at 95%confidence level. This proposed method was successful in the determination of iron(III) in fruit juice samples and provides a simple, cost-effective, high precision and alternative to other methods.