Reference tocopherols, DL--T (>96%) from Sigma Chemicals,
rac--T(90+%), -T (99%) and -T (93.7%) were purchased from
Supelco (Bellefonte, PA, USA). Ethyl acetate and n-hexane were
HPLC grade and were obtained from POCH S.A. (Gliwice, Poland).
Carbon dioxide (99.5%) was obtained from Linde Gas (Poland).
The fine-grain sand for Soxhlet and SFE extractions was sieved
on sieves and fractions of 0.2–0.3 mm were collected. Then, the
sand was purified by successive elution with warm distilled water,
methanol and hexane. The sand was dried after each stage of elu