GC/MS/MS quantification of 11-dehydrothromboxane B2 in human urine.
A fully validated stable isotope dilution method for rapid quantification of 11-dehydrothromboxane B2 by gas chromatography/negative chemical ionization tandem mass spectrometry is reported. The interassay coefficient of variation was 1.3%. The relative recovery of synthetic, underivatized 11-dehydrothromboxane B2 added to urine was 84.6 +/- 2.5% (mean +/- SEM, N = 9). The equation of the regression plot correlating the amounts added and recovered was Y = 0.894X-0.23, with R = 0.9963. The late introduction of the pentafluorobenzyl moiety at C11 afforded distinct advantages in the cleanup stage of the assay and during the GC/MS analysis as well. The pair of daughter fragments at m/z 345 and 349 of the parent fragment ions at m/z 615 and 619 were monitored. Excretion values of 11-dehydrothromboxane B2 in 3 healthy male subjects were 975, 615 and 822 ng/24 h. Excretion was reduced to 751, 387 and 465 ng/24 h, respectively, after administration of a fish oil supplement (15 g/day) for 10 weeks.
Ferretti
A
A
Beltsville Human Nutrition Research Center, Lipid Nutrition Laboratory, MD 20705.
Flanagan
V P
VP
Maida
E J
EJ
D002851:Chromatography, High Pressure Liquid; D005395:Fish Oils / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine
D005395:Fish Oils; D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2