Determination and quantification of urinary metabolites after dietary exposure to acrylamide

Abstract

It is known that heat-treated carbohydrate-rich foods may contain high levels of acrylamide (AA) and up to 4000 µg kg⁻¹ in potato crisps and 2000 µg kg⁻¹ in French fries have been reported. In order to obtain more information on the human exposure to and metabolism of AA, a method for the determination of known urinary metabolites from the dietary exposure of AA using solid-phase extraction and liquid chromatography with positive electrospray MS/MS detection was developed. The validated assay range was from 8.6 to 342.9 µg l⁻¹. The urinary metabolites were synthesized and their structures determined by NMR and MS. To test the method, a pilot study was conducted in which all urine during 48 h starting with 24 h fasting was collected. The two urinary metabolites, N-acetyl-S-(3-amino-2-hydroxy-3-oxopropyl)cysteine (MA-GA₃) and N-acetyl-S-(3-amino-3-oxopropyl)cysteine (MA-AA), were found to be above the detection limit. Fasting during 1 day caused about a 50% decrease in the total level of the metabolites, but after 1 day of a normal diet, the metabolite levels increased back to pre-fasting levels. The total amount of AA in the form of urinary metabolites excreted over the period was estimated to be about 40 µg AA day⁻¹ for the average non-smoker.

Keywords :

• Acrylamide
• glycidamide
• urinary metabolites
• biomarkers
• dietary exposure

Acknowledgements

The project was supported by a grant from the Research Council of Norway. Additional funding is acknowledged from the European Commission, Priority 5 on Food Quality and Safety (Contract No. FOOD-CT-2003-506820 Specific Targeted Project), ‘Heat-generated Food Toxicants — Identification, Characterisation and Risk Minimisation’. The present paper reflects the authors’ views and not necessarily those of the European Union. There is no guarantee or warranty that the information provided is fit for any particular purpose. The user thereof uses the information at his own risk and liability.