Gas density balance and the mass chromatograph

Abstract

a straight line for an initial Gaussian distribution, and any deviations from straight-line behavior would give information on the initial pulse shape. CONCLUSIONSPlasma chromatography has been used largely as a simple detection or characterization tool, but the existence of a highly-developed kinetic theory of ion mobility and diffusion should make it capable of greater scope. Much useful information can be gained by the systematic variation of operating parameters much as temperature, gas pressure, and electric field, the use of various drift gases or gas mixtures, and the study of pulse widths and shapes. Further advances can be expected in the correlation of diffusion cross-sections with molecular structure. ACKNOWLEDGMENTThe authors thank T. H. Vu for his help with many of the calculations, and D. I. Carroll for his many helpful comments.A theoretical development is presented to show the hydrodynamics of operation of the gas density balance (a gas chromatographic detector that is currently being used in the mass chromatograph). Theoretical aspects of the mass chromatograph and a formal derivation of its operational relationships are also presented and discussed.I Present address, SEKA, C e n t r a l Research L a b o r a t o r y , I z m i t , T u r k e y .The gas density balance was first introduced in 1956 ( I ) . Its design was motivated by a desire to develop a gas chromatographic detector where response would be independent of the chemical structure of the substance being analyzed. The detector can be used for determination of molecular weights (2, 3 ) and in a modified form ( 4 ) , which has become known as the Gow-Mac gas density balance ( 5 ) , it is currently being used in the mass chromatograph (6).

Gas chromatography

“…Perhaps the most powerful application of the gas density balance is for molecular weight determination. A theoretical analysis of the hydrodynamics of the detector presented its operational relationships (865). Swingle (1513) presented a quantitative treatment of the errors in mass and weight percent measurements.…”

Pyrolysis–molecular weight chromatography–vapor‐phase infrared spectrophotometry: An on‐line system for analysis of polymers. IV. Influence of cis/trans ratio on the thermal degradation of 1,4‐polybutadienes

“…Theoretical aspects of the mass chromatograph have been reported elsewhere (2); earlier papers introduced the pyrolyzer-mass chromatograph techniqu e (3 , 4). Parts II and III of this series dealt with the thermal decomposi tion of polyolefins (5) and p o l y ole f i n sulfones ( 6 ) , respective ly .…”

Quantitative gas chromatography without analyte identification by ultrasonic detection

“…Normally, when quantitation is performed, a response factor is obtained from the known molecular weights of the analyte and the carrier gas (16)(17)(18). In separate studies, such a detector has been adapted for determining molecular weights of analytes (19)(20)(21). Thus, absolute quantitation should be possible by combining these two approaches.…”