Evaluation of a microwave assisted extraction prior to high performance liquid chromatography for the determination of additives in polyolefins

This work presents a method for the reliable determination and quantitation of frequently used stabilizers in polyolefins. The extraction of the stabilizers from the polymeric matrix was investigated for several different solvents and solvent mixtures in a monomode microwave reaction system. Ethyl acetate showed the best extraction performance with respect to easy and rapid sample preparation. For this solvent, a systematic and comprehensive survey of time- and temperature-dependence of extraction efficiency was carried out. Extractions utilizing ethyl acetate for 30 min at 130 °C showed the best overall performance for all investigated analytes. Additionally, the influence of the physical form of the sample was investigated. The extraction of pellets and powder was compared and, regardless of the physical form, the reproducibility for the whole method developed for all chosen analytes was below 2%.