Canadian Medical Guide > Analytical, Diagnostic and Therapeutic Techniques and Equipment > Investigative Techniques > Chemistry, Analytical > Spectrum Analysis > Spectrum Analysis, Mass Terms and Definitions




Spectrum Analysis, Mass

Medical Definition: Analysis of the mass of an object through means of determining the wave length(s) at which electromagnetic energy is absorbed by that object.
Guide Notes: mass refers to the mass of the object being analyzed; NIM
Previously Indexed: Spectrum Analysis (1966-1970)
Spectrum Analysis, Mass Categories.
Canadian Medical Guide Definition Spectrometry, Mass, Electrospray Ionization - A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
Canadian Medical Guide Definition Spectrometry, Mass, Fast Atom Bombardment - A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.
Canadian Medical Guide Definition Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
Canadian Medical Guide Definition Spectrometry, Mass, Secondary Ion - A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (keV) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. Digital imaging can be generated from the secondary ion beams and their intensity can be measured. Ionic images can be correlated with images from light or other microscopy providing useful tools in the study of molecular and drug actions.

Spectrum Analysis, Mass Medical Definitions and Terms

CANADIAN MEDICAL GUIDE

Thank you for visiting Canadian Medical Guide .com





Wildlife On Video »

Canadian Medical Guide Canada's Great Outdoors
Tour Canadian Rockies »
Book Banff »
Book Jasper »
Maligne Lake Boat Cruise »
Gondola Banff »
Hike Jasper »
Jasper Columbia Icefield »