Voltage alternator, accelerating

Mass Spectrometry — The mass spectrometers and associated equipment have been described in detail (9). In brief, an LKB 9000 GLC-MS (a magnetic sector instrument) was utilized with a modified accelerating voltage alternator (AVA) (12). For A 9-THC the mass spectrometer was set to focus alternately on the ions... 

In the first two methods, described above, the distillate solutions were subjected to standard gas chromatography combined with mass spectrometry instrument. In the third method a quantitative mass spectrometric analysis of methylmercury was performed using the combined instrument supplied with an accelerating voltage alternator (AVA unit) >. ... 

Accelerating voltage (high voltage) scan. An alternative method of producing a momentum (mass) spectrum in magnetic-deflection instruments. This scan can also be used, in conjunction with a fixed radial electrical field, to produce an ion kinetic energy spectrum. 

In contrast to the polyacrylamide homopolymers typical of CE,Fujimoto et al. incorporated charged functionalities into the neutral polyacrylamide chains to accelerate the migration of neutral compounds through a capillary column [90]. Despite this improvement, nearly 100 min were required to effect the separation of acetone and acetophenone, making this approach impractical even with the use of high voltage. Alternatively, Tanaka et al. [86] alkylated commercial poly-allylamine with alkyl bromides, followed by a Michael reaction with... 

Transmission Electron Microscopy. A Philips model 201 (Arvada, CO) transmission electron microscope was used as an alternative method for determining the particle sizes of Ludox silicas. Specimens were prepared on formvar-coated, 200-mesh copper specimen grids. Typical acceleration voltages and magnifications were 80 kV and 65,000X. 

Fig. 4 shows the principle of the mass separator, consisting of an array of electrodes. Its principle is based on a traveling wave. Ions enter the mass separator on the left hand side at a kinetic energy determined by the potential of the acceleration electrode, which results in a velocity of the ions which is inversely proportional to the root of their mass. Ions at a specific mass and an acceleration voltage will travel synchronously to the traveling alternating dipole field, as shown in fig. 4. In principle both the bold... 

Procedure for measuring the accurate mass of an ion using scanning mass spectrometers, in which the peak corresponding to the unknown ion and that for a reference ion of known m/z are displayed alternately on a display screen and caused to overlap by adjusting the acceleration voltage. 

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