Comparison of pressurised fluid extraction and microwave assisted extraction with atmospheric pressure methods for extraction of additives from polypropylene

Extraction of Irganox 1010 from freeze-ground polypropylene using several methods has been compared. Pressurised fluid extraction (PFE) (of which accelerated solvent extraction is an example) using a modified supercritical fluid extractor (SFE) and microwave assisted extraction (MAE) both gave faster extraction than any conventional method, and recoveries were not significantly different. The times taken to reach 90% extraction for PFE using propan-2-ol at 150 °C and acetone at 140 °C were 5 and 6 min, respectively. Reflux with chloroform was found to be the fastest atmospheric pressure method with 90% extraction in 24 min. Reflux with cyclohexane–propan-2-ol (1 + 1) required 38 min; ultrasonic, shake-flask and Soxhlet extraction required about 80 min (90% extraction). For effectively complete extraction, from loaded extraction vessel to extract ready for analysis, PFE required 15 min, MAE 28 min and reflux with chloroform 45 min.