Determination and quantification of urinary metabolites after dietary exposure to acrylamide

It is known that heat-treated carbohydrate-rich foods may contain high levels of acrylamide (AA) and up to 4000 mu g kg(-1) in potato crisps and 2000 mu g 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 mu g 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-GA(3)) 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 mu g AA day(-1) for the average non-smoker.