Pittfalls associated with the use of liquid chromatographytandem mass spectrometry in the clinical laboratory. Clin Chem 2010;56:1234–44

such as atmospheric pressure ionization and tandem mass spectrometry have substantially extended the spectrumof clinical chemistrymethods during the past decade. In particular, liquid chromatography tandem– mass spectrometry (LC-MS/MS) has become a stan-dard tool in research laboratories as well as in many clinical laboratories. Although LC-MS/MS has features that suggest it has a very high analytical accuracy, po-tential sources of inaccuracy have recently been identified. CONTENT: The sources of inaccuracy in LC-MS/MS methods used in the routine quantification of small molecules are described and discussed. Inaccuracy of LC-MS/MS methods can be related to the process of ionization through the insource transformation o