Liquid chromatography/mass spectroscopy (LC/MS) is a versatile analytical method commonly employed during all phases of pharmaceutical drug development because of its regarded speed, sensitivity, and selectivity. It is commonly used during final analyses of the drug approval process. LC/MS identifies proteins, detects metabolites, determines the molecular weight of drugs, verifies molecular structures and detects for impurities and degradants. Purchasing considerations for pharmaceutical LC/MS systems include the desired ionization method, instrument size, ease of use and operation, and the laboratory budget.