Sampling and Analytical Method for Alpha-Dicarbonyl Flavoring Compounds via Derivatization with o-Phenylenediamine...

Area of Science:

• Analytical Chemistry
• Occupational Health and Safety
• Food Science

Background:

• Diketones such as diacetyl, 2,3-pentanedione, 2,3-hexanedione, and 2,3-heptanedione are volatile compounds found in food and flavoring industries.
• Worker exposure to these diketones can pose significant health risks, necessitating reliable monitoring methods.

Purpose of the Study:

• To develop and validate a novel sampling and analytical methodology for diacetyl and related diketones.
• To establish a method for evaluating and monitoring worker exposure in the food and flavoring industry.

Main Methods:

• Airborne diketones were collected on o-phenylenediamine-treated silica gel tubes.
• Analytes were derivatized on-tube to stable quinoxaline derivatives.
• Analysis was performed using gas chromatography/nitrogen-phosphorous detection (GC/NPD).

Main Results:

• Achieved limits of detection (LOD) in the range of 5-10 nanograms/sample.
• The on-tube derivatization was quantitative across a wide range of concentrations (0.1 μg to 500 μg) and unaffected by humidity (20%-80%).
• Derivatives demonstrated stability for 30 days, and quantitative recovery was achieved for large sampling volumes (up to 72 L at 50 cc/min).

Conclusions:

• The developed method provides a sensitive, robust, and stable approach for sampling and analyzing target diketones.
• This methodology is suitable for long-term air monitoring, enabling comprehensive assessment of worker exposure over an 8-hour shift (up to 288 L).
• The method is vital for occupational health assessments in industries where diketone exposure is a concern.