As we have already discussed in Part I, “Analytical Chemistry I”, in general on the subject of ‘Analytical Methods’, a distinction between non-destructive methods and spectroscopic methods in which the analyte is altered or even completely destroyed is also made in molecular spectroscopy. This part of the book will deal on the one hand with different methods of mass spectrometry, in which the analytes are fragmented (i.e. “torn to pieces”), and on the other hand with nuclear magnetic resonance spectroscopy, in which, depending on the methodology, it is quite possible to recover the analyte intact after the measurements have been completed (even if this can occasionally be a little tricky).