| Size of sample (PS) | Extraction yield | |
| Soxhlet | Methanol:Chloroform | |
| Large (PS > 2.36 mm) | 2.38% | 3.19% |
| Medium (2.36 mm > PS > 0.5 mm) | 7.95% | 6.72% |
| Small (0.5 mm > PS > 0.35 mm) | 11.67% | 8.9% |