A sensitive method for very-long-chain
fatty acid analysis was developed by gas chromatography-
nitrogen-
phosphorus detection by using cyanomethyl derivatization.
Bromoacetonitrile as alkylating
reagent was used to improve
nitrogen phosphorus detection detectability of compounds containing non-
nitrogen. The carboxyl group of very-long-chain
fatty acid was alkylated to cyanomethyl
esters. Reaction conditions were 40 min at 60 degrees C under
potassium carbonate base. Heptacosanoic
acid was used as an internal standard and
hexane was used as a
solvent of extraction. The extraction yield was 82.8% or more, relative standard deviation of the precision test was 8.3% or more and the result of linearity test showed a good correlation coefficient of r2=0.999 in the range of 0.1-50 microg/ml. The quantification limits were 10 ng/ml when 0.5 ml of serum was used. The present method proved simple, rapid, inexpensive and resistant to contaminants. When it was applied to serum samples taken from patients with
X-linked adrenoleukodystrophy which is a hereditary X-linked disorder characterized by progressive
demyelination and
adrenal insufficiency during childhood, relative increase of the concentration of
hexacosanoic acid and the concentration ratios of hexacosanoic, lignoceric to
behenic acid was observed in comparison with control samples.