Serum VE was analyzed as described by Kayden et
al. (1973) with modifications. Briefly, samples were saponified
by mixing 1 mL of serum with a 2% pyrogallol
solution (5 mL) and heated for 2 min in a 70°C shaking
water bath. The tubes were removed and 0.25 mL of 11
N KOH was added. The tubes were heated again in a
shaking 70°C water bath for 30 min and then placed in
an ice bath. Two milliliters of hexane (used to extract
the VE) and 0.5 mL of water were added to the saponified
samples and shaken vigorously for 2 min. One
milliliter of the hexane layer was transferred to a 4-mL
glass test tube for analysis. Standards of 1, 2, 4, 6, 8,
and 10 μg/mL of α-TOH were prepared at the same
time. A 0.2% bathophenanthroline solution (200 μL)
was added to all the samples and standards