Development of novel methods for quantitative metabolite profiling of candidate pharmaceutical drugs via the combination of high-performance liquid chromatography and ICP-mass spectrometry as a very sensitive and element-selective detector. Advantages of this approach are the fact that no radiolabeling is required, while the signal intensity is independent of the structure of the molecule in which the target element is present. An extension of the application range via "marking" of molecules with an ICP-MS detectable element will be aimed at.