Microwave-assisted extraction by fast sample preparation for the systematic analysis of additives in polyolefins by high-performance liquid chromatography

This paper presents a new approach for complete and systematic analysis of organic additives in polyolefins. The proposed procedure is a convenient co mbination of sample preparation, performed by microwave-assisted extraction (MAE), and direct chromatographic evaluation of extract by high-performanc e liquid chromatography coupled with ultraviolet and evaporative light scat tering detection. In particular two microwave-assisted processes are report ed and discussed: the one-step MAE, useful for additives with low-medium di polarity (like stabilizers, flame retardant, antistatics, slip and processi ng agents), and the two-step MAE, useful for additives with either high dip olarity (like organic salts, antigasfading, antiacid, nucleating agent) or high molecular mass (like polymeric hindered amine light stabilizers). Both the proposed processes have been tested on representative additives in fiv e commercially common polymeric matrices, demonstrating their satisfactory analytical results, in terms of repeatability and percentage recoveries, an d their good performances, in terms of safety and time/solvent consumption, in comparison with those of traditional extraction methods. (C) 2000 Elsev ier Science B.V. All rights reserved.