Glycidyl fatty acid esters in food by LC-MS/MS: method development.

Area of Science:

• Analytical Chemistry
• Food Chemistry
• Mass Spectrometry

Background:

• Glycidyl fatty acid esters (GE) are process contaminants found in refined edible oils and fats.
• Accurate quantification of GE is crucial for food safety regulations and risk assessment.
• Existing analytical methods may lack sensitivity or specificity for reliable GE determination.

Purpose of the Study:

• To develop and validate an improved analytical method for quantifying five key glycidyl fatty acid esters in edible oils.
• To incorporate stable isotope dilution analysis (SIDA) for enhanced accuracy and precision.
• To achieve lower method detection limits compared to previously published methods.

Main Methods:

• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) with positive ion atmospheric pressure chemical ionization.
• Stable isotope dilution analysis (SIDA) using deuterium-labeled internal standards.
• Two-step solid-phase extraction (SPE) cleanup using C18 and silica cartridges.
• Analysis of glycidyl esters of palmitic, stearic, oleic, linoleic, and linolenic acids.

Main Results:

• The developed LC-MS/MS method demonstrated high sensitivity, with detection limits as low as 1-3 μg/kg when using a 0.5 g oil sample.
• Average recoveries for the five target glycidyl esters ranged from 84% to 108%.
• The method achieved detection limits 5-10 times lower than published methods, particularly when using larger sample sizes.

Conclusions:

• The developed LC-MS/MS method with SIDA provides a sensitive, specific, and accurate approach for glycidyl fatty acid ester analysis in oils.
• This method enables more reliable monitoring of GE levels in food products, contributing to improved food safety.
• The technique is suitable for routine analysis and surveys of GE in the food industry.