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The mass spectrometer for planetary exploration (MASPEX) is a versatile mass spectrometer with unprecedented mass resolution designed for spaceflight. However, the current version of MASPEX is desi...

We present a novel, innovative approach to gas chromatography-mass spectrometry (GC-MS) based on micro-electro-mechanical systems (MEMS) columns that improve the current, state-of-the-art by dramatically reducing the size, mass, and power resources for deploying GC for future landed missions. The outlet of the MEMS GC column was coupled to a prototype of the MAss Spectrometer for Planetary EXploration (MASPEX) through a heated transfer line into the ion source. MEMS GC-MS experiments were performed to demonstrate linearity of response and establish limit of detection (LOD) to alkanes (organics), fatty acid methyl esters (FAMEs) and chemically derivatized amino acids (biological molecules). Linearity of response to each chemical family was demonstrated over two orders of magnitude dynamic range and limit of detection (LOD) values were single to tens (4–43) of picomoles per 1 μl injection volume. MEMS GC column analytical performance was also demonstrated for a “Mega Mix” of chemical analytes including organics and biological molecules. Chromatographic resolution exceeded 200, retention time reproducibility was << 1% RSD (majority ≤ 0.3%), and peak capacity values calculated to be 124 ± 2 over a 435 s retention time window. The 5.5 m MEMS column was also shown to be a suitable alternative to traditional commercial columns for use in comprehensive two-dimensional gas chromatography (GC × GC). Mass spectra collected from MASPEX showed close consistency with National Institute of Technology (NIST) reference mass spectra and were used for high confidence identification of all eluting analytes.

Mass spectrometry is a powerful tool to measure the composition of volatile and semi volatile gases. The necessity to accurately identify and quantify unknown species lead to the requirements of a mass spectrometer as the detector of choice in most separation science and direct sample analysis situations. Advantages of time-of-flight mass spectrometry (TOFMS) are the high mass resolution, high mass range, and the measurement of the entire mass range in each extraction. The multi-bounce time-of-flight mass spectrometer (MBTOF) described in this work, takes advantage of a small footprint without sacrificing mass resolution. To achieve this, the MBTOF prototype uses a linear flight path with dual lens stacks. Ions are bounced in between the mirrors for a specified duration whereby increasing their flight time and resolution. The number of bounces can tune the resolution of the instrument. To show the minimum capabilities of the instrument and further applications of it, MBTOF was operated in linear mode. The instrument is designed for a multibounce passage of the ion optics and the focal point of the ion optics is optimized for this application, therefore the resolution in linear mode is limited. However, even in linear mode of operation, the mass resolution meets or exceeds that of a quadrupole mass spectrometer with limited power supplies required for operations. The measurements presented here are based on lab measurements of the early lab prototype MBTOF operated in a linear flight mode with low ion source extraction fields. A detailed evaluation including filament characterization, dynamic range and resolution are investigated. Further discussion involving applications on planetary missions for rocket science, coupling of MBTOF with laser thermal desorption or gas chromatography for potential organic determination in deep space are included.

The purpose of this work is to expand on the theory presented by Silveira et al. [ Silveira et al., International Journal of Mass Spectrometry 296 ( 2010 ) 36–42 ], to include a detailed discussion of discrete ion transport properties in the periodic-focusing DC ion guide (PDC IG) that result in radial ion focusing and ion mobility. We previously noted that although the PDC IG utilizes only electrostatic fields, ions are subjected to an effective RF as they traverse the device in the axial ( z ) direction. Here, the radial electric field ( E r ) oscillations generating the effective RF are investigated in detail. Equations of motion are derived to explain ion movement in the radial ( r ) direction. The results suggest that a collisionally dampened effective potential ( V *) model can explain the observed radial ion confinement. Furthermore, a mathematical explanation regarding the effects of the non-uniform axial electric field and periodic collisional cooling phenomena generated in the PDC IG is presented in the context of ion mobility spectrometry (IMS). Included is a detailed discussion of the ion mobility coefficient ( K ), ion mobility resolution ( R ), and subsequent determination of the ion-neutral collision cross section ( Ω ) using the PDC IG. The results indicate that the PDC IG affords straightforward and accurate determination of K and Ω via incorporation of a mobility damping coefficient ( α ) which is easily derived based upon the operating conditions and the electrode geometry.

The resolution of ion mobility spectrometry (IMS) is of paramount importance for both post-ionization separations and structural characterization of ions that have similar ion-neutral collision cross sections; however, the instrumental features that lead to increased resolution also decrease ion transmission through the drift cell. The periodic-focusing DC ion guide (PDC IG) drift cell provides increased ion transmission with minimal loss in resolution. In earlier work we showed that the electrode geometry (inner diameter, thickness, and spacing) strongly affects ion focusing and ion transmission. Here, we critically evaluate the effect of the electrode geometry of a PDC IG drift cell on both ion transmission and resolution. In this study we examine two drift cells that differ in length (63 and 125 cm) and electrode configuration. We also examine the effects of applied voltage and pressure in an attempt to maximize both resolution and ion transmission. Experimental data obtained with fullerene and model peptide ions are compared with calculated ion trajectories using SIMION 8.0 simulations.

A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a "perfect focus" mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.(3)) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.