A Mass Spectrometer for Continuous Gas Analysis

Abstract

An instrument for recording continuously the relative abundance of gases in a three component mixture is described. High accuracy of analysis has been sacrificed in favor of high speed response since the instrument was designed primarily for use in the investigation of respiratory problems. An instantaneous change in gas composition will appear on the record with a lag of less than 0.2 second and will require approximately 0.1 second to settle on this new value.

A large-radius high-mass-resolution multiple-collector isotope ratio mass spectrometer for analysis of rare isotopologues of O2, N2, CH4 and other gases

“…Gas-source magnetic-sector isotope-ratio mass spectrometers (IRMSs) have been the primary tool for stable isotope analysis of gases dating back to Alfred O. Nier's original design in 1947 [1]. While numerous improvements followed, including addition of more collectors [2] and enhancements in vacuum systems and gas delivery [3,4], the basic design remained largely unchanged until very recently. Virtually all gas-source multiplecollector isotope ratio mass spectrometers in use today are single-focusing magnetic sector instruments with a radius, R, of ≤ 250 mm and a dispersion, D, of ≤ ~ 500 mm (D ~ 2R for stigmatic focusing and unit magnification [5]), similar to the original Nier single-focusing design with R = 200 mm.…”

Measurement of human energy expenditure, with particular reference to field studies: an historical perspective

“…Another early electronic innovation came from Herman Rein; in his apparatus, the expirate was passed through a divided capillary resistance, with potassium hydroxide absorbing carbon dioxide in one of the two capillaries, and flow differentials being detected by the cooling of thermal sensors (Rein 1933). Other options that were considered included interferometric gas analysis (Benzinger and Kitzinger 1946), and mass spectrometry (Hunter et al 1949). During the 1950s, the non-dispersive infra-red analyzer of Luft and Fowler became the most popular option for carbon dioxide determinations (Dubois et al 1952;Fowler 1949).…”

Blood Gas Transport

“…It is generally conceded that, at least in conditions of normalcy and rest, the major portion of the alveolar-systemic arterial blood p02 difference arises from inequalities of ventilation-perfusion relation ships (the exact nature of which is still to be elucidated) rather than a true WOOD alveolar membrane gradient. In addition to the clarification of the nature of alveolar samples made possible by continuous sampling and high speed electronic gas analyzers (25,26,27), Forssander & White (28 to 31) and Brown,Hatch & Cook (32) have developed improved methods for spot sampling of gas from the respiratory airway. The possibility of using iso topes in the study of dynamic alveolar and blood gas exchanges has not been fully explored (32 to 35).…”