Green Analytical Chemistry in Teaching Laboratory:Spectrophotometric Determination of Fe Ions with Using Green Tea to Demonstrate the Principles of Sequential Injection Analysis

An interesting, simple and an inexpensive experiment that can be successfully applied in student laboratory for the course of green analytical chemistry was proposed. The students have goal to design SIA method through experiments optimization and finally take advantage of this method in the analysis of real samples. Optimization procedures of SIA system are suggested and the achieved results presented. The proposed method, based on reaction between green tea polyphenols and Fe ions, can allowed the determination of Fe ions in the concentration range of 4×10-5 to 4×10-4 mol/L with sample throughput 122 h-1. The formed stable complex has the absorption maximum at λ = 570 nm. This optimized method was successfully applied to the determination of Fe ions in laboratory samples and pharmaceuticals.