A new method using simple solid phase extraction for the rapid gas-chromatographic mass-spectrometric determination of 11-dehydro-thromboxane B2 in urine.
A new gas-chromatographic mass-spectrometric method for the rapid determination of 11-dehydro-thromboxane B2 in urine, the major metabolite of systemic thromboxane formation, has been developed. Excellent sample clean-up was obtained in a single step by adsorption of 11-dehydro-TXB2 on phenylboronate cartridges, vigorous polar and organic washing and elution with an acidic methanol mixture. Then the pentafluorobenzylester trimethylsilylether derivative of 11-dehydro-TXB2 was formed and quantified in isotope dilution technique by negative chemical ionisation gas-chromatography tandem mass-spectrometry. The daughter fragments m/z 243/247 of the parent ion m/z 511/515 were monitored. Recovery was linear and quantitative over a wide range, accuracy was 95 + 7% and precision was 11% down to the very low pg range in biologic samples. Independent validation of this very fast extraction method with a reference method applying extensive sample purification with consecutive reversed and straight phase extraction, precolumn derivatisation, reversed phase high pressure liquid chromatography and tandem gas-chromatography mass-spectrometry gave excellent agreement of values. Values for 11-dehydro-TXB2 excretion in 8 healthy controls were 501 + 298 (range 231 to 1141) ng/g creatinin. Excretion was suppressed by aspirin, moderately elevated in heavy smokers (range 680 to 1540) and increased in patients with venous thrombosis or pulmonary embolism (2370 to 13350 ng/g creatinin). This rapid extraction method is useful for the highly specific and sensitive determination of 11-dehydro-TXB2 in large sample numbers.
Lorenz
R
R
Medizinische Klinik Innenstadt, Universität München, West Germany.
Helmer
P
P
Uedelhoven
W
W
Zimmer
B
B
Weber
P C
PC
D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine
D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2