A new approach for sulfite determination by headspace liquid-phase microextraction with an optical probe

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Sulfite determination is crucial for food and beverage quality control.
• Traditional methods for sulfite analysis can be complex and time-consuming.
• Limitations exist in current online monitoring techniques for sulfite.

Purpose of the Study:

• To develop a new, improved method for sulfite determination.
• To address challenges in online analytical signal processing for sulfite analysis.
• To create a sensitive, selective, and reproducible method for sulfite quantification.

Main Methods:

• Utilized headspace liquid-phase microextraction with an optical probe (HS-LPME-OP).
• Employed 5,5'-dithiobis-(2-nitrobenzoic) acid (DTNB) as the acceptor phase.
• Monitored absorbance at 412 nm for sulfite quantification after SO2 release and extraction.

Main Results:

• Achieved a linear calibration range from 32 to 320 μg L⁻¹ for sulfite.
• Established a detection limit of 14 μg L⁻¹ for sulfite.
• Demonstrated high sensitivity, selectivity, and reproducibility of the method.

Conclusions:

• The developed HS-LPME-OP method is effective for online sulfite determination.
• Successfully applied the method to analyze sulfite in juice, alcoholic beverages, and jam.
• The new approach overcomes previous limitations in extraction phase retention and online processing.