Report of an interlaboratory comparison organised by the European Reference Laboratory for Food Contact Materials : Formaldehyde in 3% acetic acid migration solution -follow up exercise

Abstract

This report presents the results of the 2013 follow up of the EURL-FCM 2012 ILC formaldehyde and melamine in food contact migration solution. In the 2012, out of the 62 laboratories who submitted results, 23 laboratories (ca. 37%) had results that showed some discrepancies affecting the analysis of the highest concentration level sample. For the NRLs, for this test solutions, 10 laboratories out of 27 ( ca also 37%) had questionable or unsatisfactory scores. Therefore, as a follow up, the EURL sent prepared a new migration solution for underperforming laboratories to repeat this part of the ILC and improve their results. The test material used for preparation of the migration solution were melamine kitchenware (spoons) containing formaldehyde. The general aim of the exercise was to assess once again the performance of the official control laboratories which had some issues in the determination of formaldehyde in high concentrated solution where the dilution step was necessary. There were 23 participants to whom samples were dispatched and all laboratories submitted results (10 NRLs + 13 national control laboratories from European countries) and all of them submitted results. The homogeneity study was performed by the EURL-FCM laboratory. Participants were invited to report 4 results. Laboratory results were processed using DIN 38402 A45 (Q-Hampel) algorithm. The assigned values were obtained after applying the robust statistics to the results of the participants. Standard deviations for proficiency assessment (also called target standard deviations) were set based on Horwitz equation. The results of the quantification of in the migration solution of kitchenware in 3% acetic acid showed an improvement for the problematic high concentration from 63% satisfactory in 2012 to 92% satisfactory (for all laboratories indifferently of NRL or OCLs). For the NRLs, all results were satisfactory and the performance increased from 63% to 100%.JRC.I.1-Chemical Assessment and Testin