Besides all the classical HPLC-UV/PDA/Fluorescence/ECD/flow-ionization possibilities (the latter for tracer studies), ABL has the disposal of eight LC-MS/MS systems (all Sciex quadropole tandem mass spectrometry systems). Our main platform is the Sciex API 4000 system, including one API4000-Qtrap). For more sensitivity, also a Sciex API 5500-Qtrap is available. The Qtraps are also very helpful in qualitative metabolism studies. Recently the API5500 Q-trap was also equipped with the SelexION option. With this ion-mobility option even more selectivity and sensitivity is available. Applying the SelexION option, the first application measuring femtograms per mL has recently been validated.