Identification of 9,10-epoxyoctadecanoic acid in human urine using gas chromatography-mass spectrometry.
9,10-epoxyoctadecanoic acid has been detected in human urine. Two simple purification procedures were used; the one based upon liquid-liquid extraction and the other based upon sorbent extraction technology isolating the free fatty acid fraction. Prior to trimethylsilylation and gas chromatographic-mass spectrometric analysis, both the epoxy and carboxy functions were reduced to hydroxy groups. The shift in fragmentation of a deuterated sample verified the presence of intact epoxide prior to chemical reduction. Special attention was paid to the risk of false identification of the epoxide. The content of 9,10-epoxyoctadecanoic acid in human urine was estimated to be 2.1 nM/L.
Ulsaker
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GA
Norwegian Medicines Control Authority, Oslo, Norway.
Teien
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D003903:Deuterium; D005230:Fatty Acids, Nonesterified / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods* / Q000706:statistics & numerical data; D006586:Hexanes; D006801:Humans; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide; D013229:Stearic Acids / Q000652:urine*
D005230:Fatty Acids, Nonesterified; D006586:Hexanes; D013229:Stearic Acids; C013519:9,10-epoxystearic acid; C026385:n-hexane; D012972:Sodium Hydroxide; D003903:Deuterium