Journal of Lipid Research, Vol 31, 1925-1934, Copyright © 1990 by Lipid Research, Inc.
A sensitive method for the quantification of the mass of inositol phosphates using gas chromatography-mass spectrometry
SD DaTorre, PB Corr and MH Creer
Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110.
A sensitive method to directly measure the mass of inositol phosphates from
biologic samples is described. The procedure uses ammonium sulfate gradient
elution anion exchange column chromatography to isolate inositol
monophosphate, bisphosphate, trisphosphate, and tetrakisphosphate. The
isolated fractions are dephosphorylated and subsequently desalted by a
novel approach using solid barium hydroxide in a 1:1 stoichiometric ratio
to the amount of ammonium sulfate present in the dephosphorylated sample.
The myo-inositol derived from each inositol phosphate species was
quantified by stable isotope dilution gas chromatography-mass spectrometry
of the hexakis(trimethylsilyl) derivative using hexadeutero-myo-inositol as
the internal standard. The applicability and sensitivity of this method are
illustrated by measuring the mass of individual inositol phosphates in
isolated adult canine cardiac myocytes.