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Computerized mass fragmentography and peak matching
Author(s) -
Hammar CarlGustaf,
Pettersson Gunnar,
Carpenter Paul T.
Publication year - 1974
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200010607
Subject(s) - analytical chemistry (journal) , sample (material) , range (aeronautics) , volume (thermodynamics) , pipette , chemistry , compensation (psychology) , standard deviation , resolution (logic) , chromatography , materials science , mathematics , computer science , physics , statistics , quantum mechanics , artificial intelligence , psychoanalysis , composite material , psychology
The minicomputer calculates and sets the required accelerating voltages by means of a 16 bit d.a.c. for maximum 8 masses within a 30% mass range. These, together with the t.i.c., are displayed in real time on a television screen and recorded on magnetic tape with a dynamic range of 1:32 000. Automatic fine adjustment of the mass focus and compensation for drifts in the magnetic field are some of the features in the mass fragmentographic package, which also allows data to be displayed, analysed, edited and plotted. Quantitative analyses can be handled entirely by the system if it is provided with the weight ratios of the compound to be determined and the standards to construct the standard curve. A table of the concentration per ml sample at the various times and/or a semi‐log plot may be obtained by providing the amount of the standard added to the sample (e.g. blood), the extracted sample volume and the time at which the sample was drawn. Mass determinations of isolated or non‐isolated compounds (nanogram amounts) can be performed within a few minutes with a precision usually better than 5 ppm employing a single focusing instrument at a resolution of 600–700. A maximum of seven unknown masses within a 30% range can be specified and determined simultaneously or in a preselected order. The shortest sweep time of the ion beam is 300 ms. The peak shapes can be analysed by displaying the data stored on magnetic tape on the television monitor.