If you are working with thermally labile compounds, analyses of these samples may be accomplished using the Perkin Elmer Sciex API I plus quadrupole mass spectrometer. API (atmospheric pressure ionization) is similar to ESI (electrospray ionization) and many people use the terms interchangeably as does this site . This instrument is capable of analyzing small organic, inorganic and large biological molecules. If your sample is a mixture of components or laden with salts and/or detergents (they need to be removed before analysis) usually best result are obtained by liquid chromatography - mass spectrometry (LC-MS). The facility utilizes a Applied Biosystems syringe pump HPLC system along with a choice of columns (C-4, C-8, or C-18 packing) or you can supply your own microbore or analytical column. A Thermo Separations Products HPLC pump is used with analytical columns. Using either HPLC system, UV absorbance is monitored and recorded with the acquired data digitally so that the mass spectra can be easily correlated to the UV trace. More information on ESI or LC-MS.