Headspace single-drop microextraction coupled to microvolume UV-vis spectrophotometry for iodine determination

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Iodine determination is crucial for environmental and health monitoring.
• Traditional methods often require complex sample preparation and lack sensitivity.
• Microextraction techniques offer advantages in reduced solvent consumption and preconcentration.

Purpose of the Study:

• To develop a sensitive and efficient method for iodine determination.
• To combine headspace single-drop microextraction with microvolume UV-vis spectrophotometry.
• To validate the method for analyzing iodine in diverse real-world samples.

Main Methods:

• Headspace single-drop microextraction using N,N'-dimethylformamide.
• In situ volatile iodine generation from iodide using hydrogen peroxide.
• Microvolume UV-vis spectrophotometry for quantitative analysis.
• Optimization of extraction time, acidity, and reagent concentrations.

Main Results:

• Achieved a low limit of detection (0.69 µg/L) and good repeatability (4.7% RSD).
• Demonstrated a high preconcentration factor (ca. 623) within a short extraction time (7 min).
• Established a wide calibration range (5–200 µg/L) with excellent linearity (r²=0.9991).
• Successfully applied the method to determine iodine in water, pharmaceutical, and food samples.

Conclusions:

• The developed method offers a sensitive, rapid, and effective approach for iodine quantification.
• Headspace microextraction coupled with UV-vis spectrophotometry significantly enhances detection limits compared to conventional methods.
• The technique is robust and suitable for routine analysis of iodine in complex matrices.