Chip-based quantitative capillary electrophoresis/mass spectrometry determination of drugs in human plasma.

A chip-based capillary electrophoresis/mass spectrometry (CE/MS) system is described for the on-chip separation and coupled electrospray detection of selected small drug molecule compounds. These studies include the quantitative determination of carnitine and acetylcarnitine in analytical standard solutions as well as imipramine and desipramine in fortified human plasma samples. A clinical human plasma sample was also analyzed following the normal administration of desipramine to a volunteer, and the parent drug was determined using the described chip-based CE/MS technique. In each instance, stable isotope-incorporated internal standards were used. The chip-based CE system was microfabricated from glass and coupled to a micro ion spray device constructed in-house. The atmospheric pressure ionization system employed in this work was a PE Sciex API III tandem triple quadrupole system operated in the selected ion monitoring (SIM) mode. The results from the work reported here demonstrate the feasibility for c...