Web: | mayocliniclabs.com |
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Email: | mcl@mayo.edu |
Telephone: | 800-533-1710 |
International: | +1 855-379-3115 |
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Deuterium-labeled internal standards (pregnenolone-d4 and 17-hydroxypregnenolone-d3) are added to 0.2 mL of sample. Pregnenolone, 17-hydroxypregnenolone, and the internal standards are extracted from the sample using solid-phase extraction. The extracts are then washed and dried under nitrogen. Extracts are then derivatized using hydroxylamine and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mass spectrometer has an electrospray interface and is operated in the multiple-reaction monitoring positive mode. A 7-point standard curve is extracted and derivatized with each batch of samples.(Unpublished Mayo method)
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