Author: Massspect

Application de la spectrométrie de masse au contrôle de sécurité alimentaire.

Application de la spectrométrie de masse à la sécurité alimentaire. La sécurité alimentaire est un problème grandissant de la santé publique dans tous les pays, la situation est encore plus grave dans les pays en développement. La mondialisation du commerce des aliments a changé les caractéristiques de la production des produits alimentaires. Des produits chimiques et biologiques (tableau 1) inter...

La spectrométrie de masse appliquée à l’antidopage

Application de la spectrométrie de masse dans le domaine antidopage À l’origine, la lutte antidopage était principalement menée par le comité olympique. C’est en 1999 qu’a été mise en place l’Agence mondiale antidopage (Word Anti-Doping Agency WADA). Cet organisme international est reconnu par toutes les associations sportives. On compte actuellement trente-quatre (34) laboratoires accrédités par ...

Fast Atom Bombardment (FAB)

Fast Atom Bombardment (FAB) The FAB source was developed by Barber et al in the 1980s and is also known as Liquid Secondary Ion Mass Spectrometry (LSIM). The FAB principle consists in bombarding the sample in the solid or liquid state by a beam of primary ions or fast atoms. The primary ions are formed by the electronic impact source (Figure 1), the molecules used are often rare gases such as Argo...

Electron Ionization

Electron Ionization (IE) is the oldest ion source developed for mass spectrometry, it has been invented by Dempster since 1918. This ionization source was the most common and widely used in coupling with gas chromatography, because this ion source allows to ionize compounds in gas phase, the molecules are ionized directly in their gaseous states. However, it does not allow to ionize directly molec...

Atmospheric Pressure Photoionization (APPI)

Atmospheric Pressure Photoionization (APPI) Photoionization at atmospheric pressure (APPI) has been introduced as a detection method for gas chromatography (GC). Technically the APPI source is considered APCI by changing the corona discharge by a photon lamp [1]. It consists in using a discharge lamp that generates photons having the wavelength in the ultraviolet range. If photons are absorbed by ...

MALDI (Matrix Assisted Laser Desorption Ionization)

The MALDI ion source is an analytical technique for soft ionization of molecules from solid state, thus non-volatile high molecular weight molecules are easily analyzed. This ion source was invented in 1984[1] by Karas and his colleagues[2]. In 2002 Tanaka and his colleagues received the Nobel Prize for their work about MALDI, demonstrating that a protein could be ionized by the laser using a suit...

Chemical ionization and Atmospheric-pressure chemical ionization (APCI)

Chemical ionization and  APCI Chemical ionization (CI) [1] [2] is a complementary method of electron ionization (IE). Since the ion source electron ionization is too energetic, causing too much fragmentation of molecular ions, therefore, the information of the molecular weight may be missing. The basic principle of chemical ionization is to ionize neutral molecules (methane, butane, ammonia …...