Report of an interlaboratory comparison organised by the European Union Reference Laboratory for Food Contact Materials; ILC01 2010 - Photoinitiators in solvent and in paperboard

Abstract

This report presents the results of the ILC of the EURL-FCM which focused on the screening for photoinitiators (PI) content in paperboard as well as in a solvent. The test materials used were two types of paperboard supplied by the industry, containing benzophenone (BP) and 4-methylbenzophenone (4MBP) and mixtures of five PIs in a solvent (acetonitrile) prepared in-house. The general aim of the exercise was to assess the proficiency of the official control laboratories and consequently the participants were free to use an analytical method of their choice. There were 36 participants to whom samples were dispatched (26 NRLs + 10 official national control laboratories from Germany and Spain) 32 of which submitted results. The homogeneity and stability studies were performed by the EURL-FCM laboratory. The assigned values were obtained after applying robust statistics to the results of the participants. Participants were invited to report four replicates measurements. This was done by most of the participants. Laboratory results were rated with z and z’ scores in accordance with ISO 13528 [1] Standard deviations for proficiency assessment (also called target standard deviations) were set based on Horwitz equation for substances in the solvent. For the PI paperboard the target standard deviation was set by the organizers to 15% in order to fulfil the required criteria for sufficient homogeneity of the sample within the lots. As a conclusion of the ILC exercise on the quantification of photoinitiators in the paperboard and the solvent, this ILC showed that: 1) The participation in the ILC was satisfactory regarding the number of the participating labs. Thirty-two laboratories submitted their results. From the EURL-NRL network 22 laboratories out of 25 reported results. 3 NRLs laboratories did not send any results. 2) For the network of NRL-FCM the outcome from the participation could be regarded as satisfactory as there are about 84% satisfactory results (262 out of 312) and only 3 NRLs did not participated out of 25 EURL – Food Contact Material. ILC on Pl paperboard and solvent 73 - How to obtain EU publications Our priced publications are available from EU Bookshop (http://bookshop.europa.eu), where you can place an order with the sales agent of your choice. The Publications Office has a worldwide network of sales agents. You can obtain their contact details by sending a fax to (352) 29 29-42758. EURL – Food Contact Material. ILC on Pl paperboard and solvent 74 - The mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of special interests, whether private or national. L B -N A -2 4 5 7 5 -E N -C