​Mass spectrometry is the gold standard method of chemical analysis. This is because of its general applicability, high sensitivity, and molecularly specificity. It applies to materials in all states and provides molecular, elemental, and isotopic information. It is especially valuable in characterizing the complex materials of interest in the biological and pharmaceutical sciences, in forensics, public safety, and environmental analysis. However, mass spectrometers have generally been large, delicate and restricted to use in the laboratory. To be more generally useful, and in particular to be useful to clinicians, first responders, safety officers, and on the factory floor, mass spectrometers must be miniaturized and they must produce almost instantaneous, readily understood data.