Sequential Injection Analysis of Fe(II) in Supplement Samples Using Silver Nanoclusters as Optical Sensor

A sequential injection analysis (SIA) was developed for the determination of ferrous ion (Fe(II)). The detection method was based on monitoring of surface plasmon resonance at 446 nm of the product obtained by on-line reaction of silver nanoclusters (AgNCs) with Fe(II). The experimental parameters affecting the sensitivity were investigated, including sequence order of operation, volume of sample and reagent zones, flow rate for detection, and concentration of the reagents involved. Under the selected conditions, a linear calibration for Fe(II) determination was obtained in the range of 1–30 mg L-1. The limit of detection was found at 0.3 mg L-1. A sampling frequency of 25 h-1 was obtained. The proposed method was applied for the determination of Fe(II) in supplement products with percentage recoveries obtained in the range of 87–105%. The results showed no significant difference with colorimetry and FAAS standard methods.