Accelerator mass spectrometry microdose

Sarapa, N., Hsyu, P. H., Lappin, G., and Gamer, R. C. (2005). The application of accelerator mass spectrometry to absolute bioavailability studies in humans Simultaneous administration of an intravenous microdose of 14C-nelhnavir mesylate solution and oral nelhnavir to healthy volunteers. J. Clin. Pharmacol. 45 1198-1205. 

Since the doses are very small, conventional LC-MS techniques are sometimes not sensitive enough to assay samples from microdosing studies. Often accelerator mass spectrometry (AMS) and positron emission tomography (PET) are required for obtaining PK and distribution information, respectively. As described in Section 5.4, although AMS is capable of quantifying 14C-labeled compounds with attomole (10 18M) sensitivity, the technique is not useful for distinguishing between an NCE... 

Miyaji, Y., Ishizuka, T., Kawai, K., Hamabe, Y., Miyaoka, T., Oh-Hara, T., Ikeda, T., Kurihara, A. (2009) Use of an intravenous microdose of C-labeled drug and accelerator mass spectrometry to measure absolute oral bioavailability in dogs cross-comparison of assay methods by accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry. Drug Metabolism and Pharmacokinetics, 24(2), 130-138. 

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