Determination of the MCPD fatty acid esters and glycidyl fatty acid esters in food: Report on the collaborative trial organised by the EURL-PAH and Process Contaminants

Abstract

The European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons and Process Contaminants, hosted by the Joint Research Centre of the European Commission, organised on request of the Directorate-General SANTE a method validation study via collaborative trial to evaluate the performance of a method for the determination of fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD-ester), 2-monochloropropane-1,2-diol (2-MCPD-ester) and glycidyl esters (GEs) in food samples. The method validation study was conducted according to the International Union for Pure and Applied Chemistry harmonised protocol and the Collaborative Study Guidelines of AOAC International for blind (unpaired) replicates. The method was applied for the determination of 3-MCPD-, 2-MCPD-esters and GEs in naturally contaminated oil, fat, waffles, potato chips (crisps) and crackers. The standard operating procedure was based on the extraction of the test materials by pressurised liquid extraction, followed by acid transesterification and derivatisation of the released free (non-esterified) form with phenylboronic acid. The determination was carried out by gas chromatography-mass spectrometry with electron ionisation in selected ion monitoring mode. The trial involved 10 participants, representing a cross section of research, private and official control laboratories from 4 EU Member States (Germany, UK, Ireland and The Netherlands), USA and Japan. The selection of collaborators was based on the performance in a pre-trial, organised prior to the collaborative trial with the participation of 12 laboratories. The relative standard deviation for repeatability (RSDr) ranged from 1.3 to 21%. The relative standard deviation for reproducibility (RSDR) ranged from 6.5 to 49.0%, reflecting HorRat values from 0.5 to 2.2 according to the Horwitz function modified by Thompson. However the precision was not very satisfactory (> 22% RSDR) for mass fraction levels around and lower of 100 μg/kg on fat basis. For an analyte content higher than 100 μg/kg, excellent precision was achieved with HorRat values in the range of 0.4-0.7.JRC.F.5-Food and Feed Complianc