Simplified Hydrocarbon Compound Type Analysis Using a Dynamic Batch Inlet System Coupled to a Mass Spectrometer

1997 ◽  
Vol 11 (4) ◽  
pp. 879-886 ◽  
Author(s):  
Stilianos G. Roussis ◽  
Andrew S. Cameron
1991 ◽  
Vol 5 (3) ◽  
pp. 356-360 ◽  
Author(s):  
Terrence R. Ashe ◽  
Steve G. Colgrove

2021 ◽  
Vol 217 (1) ◽  
Author(s):  
J. Simcic ◽  
D. Nikolić ◽  
A. Belousov ◽  
D. Atkinson ◽  
C. Lee ◽  
...  

AbstractTo date, a variety of different types of mass spectrometers have been utilized on missions to study the composition of atmospheres of solar system bodies, including Venus, Mars, Jupiter, Titan, the moon, and several comets. With the increasing interest in future small probe missions, mass spectrometers need to become even more versatile, lightweight, compact, and sensitive.For in situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, including 3He/4He, and other key isotopes like D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P; isotopes 13C/12C, 15N/14N, 18O/17O/16O; and disequilibrium species PH3, CO, AsH3, GeH4, and SiH4. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances.An inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled (gas, solid, or liquid) into the instrument interior, which operates at a vacuum level. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate for 1-2 hours over a range of atmospheric pressures, possibly covering 2 or more orders of magnitude, from the tropopause near 100 mbar to at least 10 bars, in an atmospheric layer of depth beneath the tropopause of about 120 km at Neptune and about 150 km at Uranus.The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS) is being developed to achieve all of these requirements. A compact, wireless instrument with a mass of only 7.5 kg, and a volume of 7 liters (7U), the JPL QITMS is currently the smallest flight mass spectrometer available for possible use on planetary descent probes as well as small bodies, including comet landers and surface sample return missions. The QITMS is capable of making measurements of all required constituents in the mass range of 1–600 atomic mass units (u) at a typical speed of 50 mass spectra per second, with a sensitivity of up to $10^{13}$ 10 13  counts/mbar/sec and mass resolution of $m/\Delta m=18000$ m / Δ m = 18000 at m/q = 40. (Throughout this paper we use the unit of m/q = u/e for the mass-to-charge ratio, where atomic mass unit and elementary charge are $1~\text{u} = 1.66\times 10^{-27}~\text{kg}$ 1 u = 1.66 × 10 − 27 kg and $1\text{e} = 1.6\times 10^{-19}$ 1 e = 1.6 × 10 − 19 C, respectively.) The QITMS features a novel MEMS-based inlet system driven by a piezoelectric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar.In this paper, we present an overview of the QITMS capabilities, including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation, especially suitable for ice giant atmospheres exploration.


1969 ◽  
Vol 24 (9) ◽  
pp. 1147-1152 ◽  
Author(s):  
H. Budzikiewicz, ◽  
H. H. Inhoffen

1. A method is described for the simultaneous monitoring of H2O, O2, CO2 and their 18O-labelled analogs in experiments on the photosynthesis both of aquatic and terrestrial plants. The apparatus consists of a Varian-MAT mass spectrometer with a modified inlet system equipped at the entrance of the ion source with a polyethylene membrane permeable for H2O, O2 and CO2.2. Experiments have been performed with Chlorella pyrenoidosa Chick. using H218O and K2C18O3 as substrates while H2O and O2 and CO2 in solution as well as their 18O-labelled analogs were monitored during dark and light periods.3. It has been observed that the isotopic composition of the photosynthetic oxygen corresponds to that of the surrounding water and differs grossly from that of the dissolved CO2 and K2CO3. It is concluded that either H2O is the precursor of the photosynthetic oxygen or that in case CO2 is involved a very fast and complete equilibration between the latter and H2O has to occur after CO2 enters the cell.


Sign in / Sign up

Export Citation Format

Share Document