Abstract
In the development of a drug candidate. radioisotope (RI) technique has been extensively used for investigating the absorption, distribution, metabolism, and excretion using experimental animals in preclinical stage due to detection with excellent specificity. However, the use of RI is limited for the protection of the radiation. In contract to RI, stable isotope (SI) is safe for the human body, and mass spectrometry makes it possible to acquire more rapid and abundant information concerning the structure of the compound to be interest. Recently, the sensitivity of SI technique has been more improved by the remarkable advance of ionization interfaces in mass spectrometory.
This paper describes an application of SI technique for quantitative analysis by mass spectrometry with regard to the measurement of fecal excretion ratio in rats by LC/MS/MS method utilizing a mixed double labeling technique with[14C] and[2H6] variants.
