Isolation and estimation of 6-ketoPGF1a by HPLC
Lipids were extracted from the serum with chloroform:methanol
(1:1). It was then filtered through a Whatman No 1
filter paper. The residue collected was evaporated to
dryness under N2, after protein estimation. Residue was redissolved
in 5 ml of ethanol and 15 ml of water was added,
acidified to pH 3 with formic acid and kept for 24 h at 4 C
with constant shaking at 2 h interval. Sample was applied to
a C18 Seppak catridge, and washed with 5 ml of water
followed by 5 ml of 15% ethanol and 5 ml of hexane. The
eicosanoids were eluted with 2.5 ml ethyl acetate.25 6-
ketoPGF1a was detected using a C18 column (isocratically
with acetonitrile:water:H3P04, 30:70:0.01, v/v, pH 2.95,
flow rate 0.5 ml/min detection at 192 nm) in a Shimadzu S
PDA 10 chromatograph.