Ionization Mechanism of Positive-Ion Direct Analysis in Real Time: A Transient Microenvironment Concept
Citations Over TimeTop 10% of 2009 papers
Abstract
A transient microenvironment mechanism (TMEM) is proposed to address matrix effects for direct analysis in real time (DART). When the DART gas stream is in contact with the sample, a transient microenvironment (TME), which can shield analytes from direct ionization, may be generated through the desorption of the matrix containing the analyte. The DART gas stream can directly ionize the matrix molecules, but the analytes will be ionized primarily through gas-phase ion/molecule reactions with the matrix ions. Experimental results showed that as little as 10 nL of liquid or 10 microg of solid was able to generate an efficient TME. Generated TMEs were able to control the ionization of an analyte below an analyte-to-matrix ratio that was dependent on the DART temperature and the boiling points of the analyte and matrix. TMEs generated by common solvents were studied in detail. The ionization of both polar and nonpolar compounds, present in a solvent or another analyte below a ratio of 1:100, were found to be mainly controlled by the generated TMEs at a DART temperature of 300 degrees C.
Related Papers
- → Direct mass spectrometric analysis of flavors and fragrances in real applications using DART(2007)108 cited
- → Nitrogen-Activated Oxidation in Nitrogen Direct Analysis in Real Time Mass Spectrometry (DART-MS) and Rapid Detection of Explosives Using Thermal Desorption DART-MS(2019)26 cited
- → Applications of Direct Analysis in Real Time (DART) Mass Spectrometry(2011)5 cited
- → Ionization Mechanisms of Direct Analysis in Real Time (DART)(2014)4 cited
- → Accurate Mass Measurements With a Reflectron Time‐of‐Flight Mass Spectrometer and the Direct Analysis in Real Time (DART) Interface for the Identification of Unknown Compounds below Masses of 500 DA(2008)6 cited