Validation by Collaborative Trial of an Isotope Dilution Liquid Chromatographic Tandem Mass Spectrometric Method to Determine the Content of Acrylamide in Roasted Coffee

Thomas Wenzl (1) , Szilard Szilagyi (1) , Johan Rosén (2) , Lubomir Karasek (1)

1 IRMM - JRC Institute for Reference Materials and Measurements [Geel]
2 Chemistry Division

A method for the determination of acrylamide in roasted coffee was subjected to method validation by collaborative trial. The aim was to extend the scope of a method already standardised for the determination of acrylamide in bakery and potato products to include roasted coffee. Modifications of the already standardised method were therefore kept to a minimum. The method was based on aqueous extraction of the roasted coffee matrix and solid phase extraction (SPE) clean-up followed by isotope dilution high performance liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). The test portion of the sample was spiked with stable isotope labelled acrylamide and extracted on a mechanical shaker with n-hexane and water for one hour. The sample extract was centrifuged, the organic phase was discarded, and a portion of the aqueous extract was further cleaned-up by solid phase extraction on an Isolute Multimode cartridge followed by a second clean-up step on an Isolute ENV+ cartridge. The volume of the acrylamide-containing fraction eluted from the second SPE column was reduced by evaporation and analysed by reverse-phase high performance liquid chromatography (HPLC) with tandem mass spectrometric detection. Three coffee samples and one aqueous acrylamide standard solution were sent to 11 laboratories from 8 EU Member States. All samples were sent as blinded duplicates. Based on the reported results the relative standard deviations for reproducibility (RSDR) were 11.5 % at a level of 160 µg/kg, 10.1 % at a level of 263 µg/kg, and 9.6 % at a level of 585 µg/kg. The values for repeatability (RSDr) in those materials ranged from 1 % to 3.5 %. The method performance parameters are satisfying with regard to internationally accepted criteria. Hence the method would be suitable for the enforcement of regulatory limits.

Mots clés: Life Sciences

Thomas Wenzl, Szilard Szilagyi, Johan Rosén, Lubomir Karasek. Validation by Collaborative Trial of an Isotope Dilution Liquid Chromatographic Tandem Mass Spectrometric Method to Determine the Content of Acrylamide in Roasted Coffee. Food Additives and Contaminants, 2009, 26 (08), pp.1146-1152. ⟨10.1080/02652030902939689⟩. ⟨hal-00573897⟩