Miniaturized Mass Spectrometry Research Articles

Application of High-Speed Gallium Nitride Devices in Mass Spectrometry Sweeping Mode

Quadrupole mass spectrometers are widely used, and voltage scanning is their traditional working mode. By fixing the scanning voltage frequency and changing the value of the RF voltage, ions with different mass numbers can reach the detector in sequence, achieving ion selection. When analyzing high-mass molecules, several kilovolts of scanning voltage are required, which is not conducive to the miniaturization and safety of the instrument. By selecting the frequency of the scanning RF power supply and fixing the value of the RF power supply voltage, ion selection can be achieved by changing the frequency of the RF power supply, enabling miniaturized mass spectrometry analysis of high-mass molecules. In this paper, a high-speed gallium nitride driver circuit for frequency scanning mass spectrometry analysis is designed. The NCP51820 high-speed gate driver and INN650D140A gallium nitride MOS tube are selected to form a full-bridge driver, realizing a quadrupole rectangular wave RF power supply. The system has a maximum withstand voltage of 650 V and a frequency range of 400 K–4 MHz, allowing for scanning measurements of mass numbers ranging from 3 to 606 amu.

Instrumentation for Detecting Sulphur Isotopes as Biosignatures on Europa and Ganymede by Forthcoming Missions

There has been remarkable progress in identifying a certain type of biosignature, both from the point of view of the payloads of forthcoming missions, and from the point of view of biogeochemistry. This progress has been due to the evolution of miniaturized mass spectrometry that can be used, under certain circumstances and for certain samples, to distinguish between putatively abiotic and biotic sulphur isotopes. These specific types of biosignatures are discussed in the context of Europa and Ganymede. Such instruments are sufficiently precise to differentiate between abiotic and biotic signatures. We reflect on new possibilities that will be available during this decade for exploring the nearest ocean worlds: Europa and Ganymede. We review arguments that point out the presence of intriguing sulphur patches on Europa’s icy surface that were discovered by the Galileo mission. These patches lead to a “sulphur dilemma”, which suggests not to focus future measurements exclusively on organics. We comment on the possibility of measurements of sulphur isotopes, as one kind of biosignature, to be complemented with additional biosignatures, in order to fully test biogenicity. These suggestions are intended to point out the best use of the available spacecrafts’ payloads during the planning of the forthcoming Jovian missions.

Fully 3D-printed carbon nanotube field emission electron sources with in-plane gate electrode

We report the design, fabrication, and experimental characterization of the first fully additively manufactured carbon nanotube (CNT) field emission electron sources. The devices are created via direct ink writing (DIW)—one of the least expensive and most versatile additive manufacturing methods, capable of creating monolithic multi-material objects. The devices are 2.5 cm by 2.5 cm glass substrates coated with two imprints, i.e. a trace made of a CNT ink (the emitting electrode), symmetrically surrounded on both sides by a trace made of Ag microparticle ink (the in-plane extractor gate). The CNT ink is a mixture of (–COOH)-functionalized multiwalled CNTs (MWCNTs), N,N-Dimethylformamide, and ethyl cellulose. Optimization of the formulation of the CNT ink resulted in a MWCNT concentration equal to 0.82 wt% and in imprints with an electrical resistivity equal to 0.78 Ω cm. 3D-printed devices having CNT imprints with active length equal to 25 mm (a single, straight trace with 174.5 μm gap between adjacent Ag microparticle imprints) and 135 mm (a square-loop spiral with 499 μm gap between Ag microparticle adjacent imprints) were characterized in a triode configuration (i.e. using an external anode electrode) at ∼2.5 × 10–7 Torr, yielding emission currents as large as 120 μA (60 μA cm−2), start-up voltages as low as 62 V and gate transmission as high as 99%. The low-cost cold cathode technology is compatible with compact applications such as miniaturized mass spectrometry, handheld x-ray generation, and nanosatellite electric propulsion.

Multivariate analysis of a nucleophilic aromatic substitution by real-time on-line flow reaction monitoring using miniaturized mass spectrometry

Multivariate analysis of a nucleophilic aromatic substitution by real-time on-line flow reaction monitoring using miniaturized mass spectrometry

Portable FAIMS: Applications and future perspectives

Miniaturized mass spectrometry (MMS) is optimal for a wide variety of applications that benefit from field-portable instrumentation. Like MMS, field asymmetric ion mobility spectrometry (FAIMS) has proven capable of providing in situ analysis, allowing researchers to bring the lab to the sample. FAIMS compliments MMS very well, but has the added benefit of operating at atmospheric pressure, unlike MS. This distinct advantage makes FAIMS uniquely suited for portability.Since its inception, FAIMS has been envisioned as a field-portable device, as it affords less expense and greater simplicity than many similar methods Ideally, these are simple, robust devices that may be operated by non-professional personnel, yet still provide adequate data when in the field. While reducing the size and complexity tends to bring with it a loss of performance and accuracy, this is made up for by the incredibly high throughput and overall convenience of the instrument. Moreover, the FAIMS device used in the field can be brought back to the lab, and coupled to a conventional mass spectrometer to provide any necessary method development and compound validation.This work discusses the various considerations, uses, and applications for portable FAIMS instrumentation, and how the future of each applicable field may benefit from the development and acceptance of such a device.

Discontinuous atmospheric pressure interface for mass spectrometry using a solenoid pulse valve.

For the development of on-site mass spectrometry for security and safety, point-of-care analysis, etc., the gas volume introduced into the vacuum should be reduced to a minimum. To cope with this demand, a discontinuous atmospheric pressure interface using a solenoid pulse valve was developed. The sample gas was introduced discontinuously into the ionization cell with a volume of 0.17cm(3) . The sampled gas in the cell was ionized by an alternating current (ac) corona discharge. The generated ions were sampled through a 0.25mm i.d. and 12mm long nickel capillary into the vacuum of a time-of-flight mass spectrometer. A gas flow rate of ~25mL/min was achieved with the 1Hz pulse valve operation and 20ms valve opening time. Sub-ng limits of detection for less volatile compounds such as explosives and drugs were obtained. Due to its compact size and low gas load to the vacuum, this new interface may be useful for applications in miniaturized mass spectrometry. Copyright © 2016 John Wiley & Sons, Ltd.

A pulsed pinhole atmospheric pressure interface for simplified mass spectrometry instrumentation with enhanced sensitivity.

A proof-of-concept pulsed pinhole atmospheric pressure interface, namely PP-API, was developed and characterized for mass spectrometry instrumentation. The PP-API was analyzed and optimized theoretically with respect to gas flow rate, opening force and dimensions. A PP-API interfaced mass spectrometry system was then constructed and tested. As a discontinuous pressure interface, the PP-API allows efficient ion transfer from atmosphere pressure ionization sources to ion traps directly. Both nano-ESI and APCI ionization sources have been successfully integrated with the PP-API interface for the detection of volatile, organic, peptide and polymer samples. The use of multiple ionization sources has also been demonstrated to enhance signal intensity, as well as avoid charge competitions in ionization sources. With simplified geometry and high ion transfer efficiency, this PP-API would enable miniaturized mass spectrometry systems with high sensitivity.

Pulse-Heating Ionization for Protein On-Chip Mass Spectrometry

An on-chip pulse-heating ionization source for protein samples was developed for the realization of miniaturized mass spectrometry. A protein analyte was ionized on a chip by applying only thermal energy to the solid phase sample without a laser, high voltage, or heated ambient gases. A fabricated ionization source consisting of a Pt/Cr microheater (width: 30 μm; length: 100 μm) on a silicon substrate was coupled with a time-of-flight mass filter to analyze a protein sample of bovine serum albumin (BSA, M = 66 kDa). A singly charged BSA ion and other multiply charged BSA ions were generated in the presence of 2,5-dihydroxybenzoic acid as a matrix. To detect the singly charged BSA ion, the required surface energy density of 1.65 × 10(-2) μJ/μm(2) was applied to the microheater for 500 ns. The use of the 2,5-dihydroxyacetophenone matrix resulted in the generation of the multiply charged protein analyte, while the use of the sinapic acid matrix showed abundant peaks in the low m/z region.

Microplasma Discharge Ionization Source for Ambient Mass Spectrometry

In this paper, we demonstrate the first use of a microplasma ionization source for ambient mass spectrometry. This device is a robust, easy-to-operate microhollow discharge that enables ambient direct analysis of gaseous, liquid, and solid-phase samples with minimum requirements in terms of operating power and high purity gas consumption. The initial performance of the microplasma device has been evaluated by ionizing samples containing dimethyl sulfoxide (DMSO), dimethylformamide (DMF), methyl salicylate, caffeine, l-leucine, l-histidine, loratadine, ibuprofen, acetaminophen, acetylsalicylic acid, and cocaine in various forms. These molecules are diverse in nature, but almost all have relatively high proton affinities. Thus, the major species observed in all obtained mass spectra corresponded to protonated molecules. Though these microplasmas are known to produce significant densities of metastable species and electrons with mean energies greater than several electronvolt, minimal fragmentation was observed. Background spectra showed prominent signals corresponding to H(+)(H(2)O)(2) ions and a distinct lack of H(3)O(+). Small water cluster ions are likely the dominant proton transfer agents, giving rise to mass spectral data very similar to that obtained using other plasma-based ambient ionization techniques. The simplicity, low cost, low power, low rate of gas consumption, and possibility of being batch-fabricated, makes these microplasma devices attractive candidates as ion sources for miniaturized mass spectrometry and other field detection applications.

ミニマスからマイクロマスヘ

The recent development of the silicon technology effects the stream of the miniaturized mass spectrometry and its system. Trend of oil less also accelerated at the same time. Old oil pump and oil diffusion pump turned to dry pump and turbo molecular pump for example. In the program of Mars exploration and other space program, mass spectrometry is one of the useful techniques to analyze the chemical components of environments. In this paper the recent development of mini size mass spectrometry, which is handy type, and micro mass spectrometry is reviewed. The improvement toward compact size mass has been taken place in the every part of mass spectrometry system from soft ionization system, mass spectrometer to pumping system. Also this improvement wipes out contamination from the overflowed sample and oil system. As the result when higher sensitivity with less sample system overcomes the detection limit of dog nose, new era for mass spectrometer will be created as one of sensors, intelligent nose.