Tandem mass spectrometry INDEX

Source Palit, M., Mallard, G. (2009) Fragmentation energy index for universalization of fragmentation energy in ion trap mass spectrometers for the analysis of chemical weapon convention related chemicals by atmospheric pressure ionization-tandem mass spectrometry analysis. Analytical Chemistry, 81,2477-2485. 

Why do we need separation techniques As will be discussed in Sections 5 and 6, state-of-the-art mass analyzers and tandem mass spectrometry allow mass spectrometry to be a powerful tool for the analysis of complex mixtures. The coupling of classical separation techniques with mass spectrometry further improves the utility of these combined techniques for mixture analysis. Mass spectrometers are the most sensitive and structure-specific detectors for separation techniques that, in general, provide more detailed and reliable structural information on components of complex mixtures than other conventional detectors (such as flame ionization, UV, reflective index detectors, etc.). 

As a result of advances in detection technology, newer HPLC detection techniques may be utilized. For example, evaporative light-scattering detection and refractive index detection may be used to quantify impurities with poor or no UV chromophore. Conductivity detection may also be used. In some cases, when no chromophore is present, chemical derivatization may be used to add a chromophore. Increasingly, tandem techniques such as liquid chromatography mass spectrometry (LC-MS) and GC-MS are utilized for impurity characterization. The highly selective nature of LC-MS ensures that few impurities are undetected. 

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