Comparison of extraction methods for determining tocopherols in soybeans

• DOI: 10.1002/ejlt.200700060
• Publication Date: 2007-09-11T12:50:02Z
• Authors: Ho Lim; Sunhee Woo; Hong Sig Kim; Seung‐Keun Jong; Junsoo Lee
• Keywords: 0303 health sciences; 03 medical and health sciences

AbstractWe evaluated the usefulness of saponification, direct solvent extraction, and Soxhlet extraction as extraction methods to determine the amounts of tocopherols in soybeans. Soxhlet extraction yielded the highest analytical values for each tocopherol homolog and was the best method for quantifying tocopherols in soybeans. Coupling of simple Soxhlet extraction with HPLC provided a highly reproducible procedure to quantify tocopherols in soybeans. The percent mean recovery ± standard deviation (n = 5) was 103.2 ± 1.21, 109.8 ± 4.18, 93.8 ± 1.12, and 106.9 ± 1.54% for α‐, β‐, γ‐, and δ‐tocopherol, respectively. The linearity test for quantification was carried out over the ranges of 0.4–10.0, 0.2–4.0, 2.0–16.0, and 0.4–10.0 µg/mL for α‐, β‐, γ‐, and δ‐tocopherol, respectively. Regression analysis showed an excellent linear relationship (R2 >0.998), and the results of the validation parameters were generally reliable and satisfactory.