Determination of 3-chloropropane-1,2-diol as its 1,3-dioxolane derivative at the μg kg⁻¹ level: Application to a wide range of foods

Abstract

This paper reports the application of a GC/MS method for the quantification of 3-chloropropane-1,2-diol (3-MCPD) at low µg kg⁻¹ levels through the determination of its 1,3-dioxolane derivative to a wide range of foodstuffs. The proposed protocol is based on the methods generally performed in control laboratories. The two main stages of the method — the solid-phase extraction and the purification of the derivatives — have been optimized. The within-laboratory reproducibility meets the official performance criteria for verifying 3-MCPD at the 20 µg kg⁻¹ limit stipulated by the European Community for soy sauce. The limit of quantification was below 5 µg kg⁻¹ for all the foodstuffs analysed. This method offers a valuable alternative to the draft CEN European Standard: instead of diethyl ether, much safer ethyl acetate is used; derivatization is more selective; and reagents are common stable chemicals. This method was successfully applied to toasted bread, savoury crackers, cheese, soups, including vegetable-based soups, meat products such as salami, vegetable oils, sauces, soy sauce and related products. Upon checking the method performance in the case of vegetable oils, the unexpected presence of monobromopropanediols was detected.

Keywords:

• 3-MCPD
• monochloropropanediol
• monobromopropanediol
• dioxolane
• solid-phase extraction
• foods

Acknowledgements

The authors gratefully acknowledge P. Blanchard for valuable advice about the chemistry of o, o-isopropylidenes derivatives and L. Szymansky for kind assistance with the mass spectrometry.