Analytical methods specific migration

Taking the multi-national project structure and the above involvement of CEN TC194/SC1/WG2 into account, the co-ordinators and all other project participants considered the methods presented (see Table 10-4) to be accepted as Europe-wide agreed analytical methods for specific migration determination of the respective monomers. The project consortium proposed the methods to the European Commission for recommendation as generally agreed or as useful methods of analysis for the Member States. 

If the steps described above could not demonstrate compliance with an SML, then specific migration must be determined analytically. After the simulant is separated from the sample (see section 5.3.1) specific migration can be determined using a wide variety of analytical techniques, such as high performance liquid chromatography (HPLC) and gas chromatography (GC) with a wide range of detection methods. 

To support the analyst in applying such controls, CEN (the European Standardisation Commission) has in TC 194 adopted and validated analytical methods for the determination of the overall migration and the migration of some specific substances. These methods are intended to be applied for testing plashc materials and articles. At national level, e.g., in The Netherlands, the methods and simulants may also be used to demonstrate compliance with national regulation of non-plastic or multilayer materials composed of plastics and non-plastics (e.g. plastic on paper, coating on metal). 

Applications Radiotracer measurements, which combine high sensitivity and specificity with poor spatial resolution, have been used for migration testing. For example, studies have been made on HDPE, PP and HIPS to determine effects of manufacturing conditions on migration of AOs from plastic products into a test fat [443]. Labelled antioxidant was determined radio-analytically after 10 days at 40 °C. Acosta and Sas-tre [444] have used radioactive tracer methods for the determination of styrene ethyl acrylate in a styrene ethyl acrylate copolymer. 

In this chapter, the main analytical techniques and the methods currently employed in industrial and research laboratories for the analysis of important classes of additives are reviewed. The use of both gas chromatographic and liquid chromatographic methods coupled with mass spectrometry features prominently. Such methodology enables the sensitive and specific detection of many types of organic additives in polymeric materials to parts per billion (jig/kg) levels. Much of the development of these methods has been undertaken as part of research into the migration or extraction of species from food-contact and medical materials [5-7], This chapter also includes some discussion on the analysis of residual monomers and solvents. 

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