Preconcentration and atomic absorption determination of iron by sequential injection analysis

Area of Science:

• Analytical Chemistry
• Environmental Science
• Spectroscopy

Background:

• Accurate determination of iron (Fe(III)) in natural waters is crucial for environmental monitoring.
• Traditional methods for iron analysis can be time-consuming and require complex sample preparation.
• Developing efficient and automated analytical techniques is essential for routine water quality assessment.

Purpose of the Study:

• To propose a sequential injection analysis (SIA) system for the atomic absorption determination of Fe(III) in natural waters.
• To integrate preconcentration and determination steps into an automated analytical procedure.
• To evaluate the performance of the SIA system in terms of retention efficiency and detection limits.

Main Methods:

• A sequential injection analysis (SIA) assembly was designed.
• A microcolumn packed with Chelex 100 chelating resin was used for iron preconcentration.
• Iron was eluted using 2 M nitric acid (HNO(3)).
• Atomic absorption determination was employed for Fe(III) detection.

Main Results:

• The SIA system automated preconcentration, elution, detection, data acquisition, and treatment.
• High retention efficiencies were observed for Fe(III) preconcentration on the Chelex 100 resin.
• Achieved detection limits were as low as 12 µg l⁻¹ (with 9 ml sample) and 6 µg l⁻¹ (with 27 ml sample).

Conclusions:

• The proposed SIA system offers an effective approach for automated Fe(III) determination in natural waters.
• The integration of preconcentration enhances sensitivity, enabling lower detection limits.
• This method provides a robust and efficient tool for environmental water analysis.