Simultaneous Analysis of Oil-Soluble, Basic, and Acidic Illegal Dyes in Foods Using Liquid Chromatography-Diode-Array...

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Chromatography

Background:

• Illegal dye adulteration poses significant risks to public health.
• Accurate and simultaneous detection methods for various dye types are crucial for food safety monitoring.

Purpose of the Study:

• To develop and validate a novel method for the simultaneous detection of 8 oil-soluble and 10 water-soluble illegal dyes in food matrices.
• To establish reliable detection limits and recovery rates for the developed analytical method.

Main Methods:

• Sample preparation involved mixing with water, methanol, and tetrahydrofuran, followed by transesterification.
• Biphasic separation allowed for selective extraction of oil-soluble dyes (organic phase) and water-soluble dyes (aqueous phase).
• Silica-gel and hydrophilic-lipophilic-balanced solid-phase extraction (SPE) were employed for sample cleanup, followed by LC-diode-array detection.

Main Results:

• The method achieved practical limits of detection (LODs) ranging from 0.5-1.0 µg/g for the analyzed illegal dyes.
• Recoveries were generally above 70% for soft drinks, chili sauce, and mustard at a spiking level of 5.0 µg/g.
• Recoveries from paprika powder ranged from 33% to 103%, indicating matrix-dependent performance.

Conclusions:

• The developed method enables simultaneous detection of a wide range of illegal oil- and water-soluble dyes in foods.
• The technique offers good sensitivity and recovery rates, making it suitable for routine food safety analysis.
• Further optimization may be needed for complex matrices like paprika powder to improve recovery consistency.