We report on a fused deposition modeling 3D-printable rotary valve fabricated from high-grade plastics such as polyether ether ketone or lower-grade plastics like polylactic acid. The valve weighs less than 90 g and has the potential to be integrated into portable and autonomous chemical analysis systems. It has been demonstrated to be leak-proof up to 2.
View Article and Find Full Text PDFCapillary temperature control during capillary electrophoresis (CE) separations is key for achieving accurate and reproducible results with a broad array of potential methods. However, the difficulty of enabling typical fluid temperature control loops on portable instruments has meant that active capillary temperature control of in situ CE systems has frequently been overlooked. This work describes construction and test of a solid-state device for capillary temperature control that is suitable for inclusion with in situ instruments, including those designed for space missions.
View Article and Find Full Text PDFWe report here the first fully automated capillary electrophoresis (CE) system that can be operated underwater. The system performs sample acquisition and analysis by coupling CE to contactless conductivity detection. Using 5 M acetic acid as the background electrolyte (BGE), inorganic cations and amino acids at concentrations as low as 5.
View Article and Find Full Text PDFCapillary electrophoresis (CE) holds great promise as an in situ analytical technique for a variety of applications. However, typical instrumentation operates with open reservoirs (e.g.
View Article and Find Full Text PDFSample injection is a critical step in a capillary electrophoresis (CE) analysis. Electrokinetic injection is the simplest approach and is often selected for implementation in portable CE instruments. However, in order to minimize the effect of sample matrix upon the results of a CE analysis, hydrodynamic injection is preferred.
View Article and Find Full Text PDFCapillary electrophoresis (CE) systems have undergone extensive development for spaceflight applications. A flight-compatible high voltage power supply and the necessary voltage isolation for other energized components can be large contributors to both the volume and mass of a CE system, especially if typical high voltage levels of 25-30 kV are used. Here, we took advantage of our custom CE hardware to perform a trade study for simultaneous optimization of capillary length, high voltage level, and separation time, without sacrificing method performance.
View Article and Find Full Text PDFScreen-printed electrodes (SPEs) coupled with flow systems have been reported in recent decades for an ever-growing number of applications in modern electroanalysis, aiming for portable methodologies. The information acquired through this combination can be attractive for future users with basic knowledge, especially due to the increased measurement throughput, reduction in reagent consumption and minimal waste generation. The trends and possibilities of this set rely on the synergistic behavior that maximizes both SPE and flow analyses characteristics, allowing mass production and automation.
View Article and Find Full Text PDFIn situ missions of exploration require analytical methods that are capable of detecting a wide range of molecular targets in complex matrices without a priori assumptions of sample composition. Furthermore, these methods should minimize the number of reagents needed and any sample preparation steps. We have developed a method for the detection of metabolically relevant inorganic and organic anions that is suitable for implementation on in situ spaceflight missions.
View Article and Find Full Text PDFThe in situ search for chemical signatures of life on extraterrestrial worlds requires automated hardware capable of performing detailed compositional analysis during robotic missions of exploration. The use of electrophoretic separations in this search is particularly powerful, enabling analysis of a wide range of soluble organic compounds potentially indicative of life, as well as inorganic compounds that can serve as indicators of habitability. However, to detect this broad range of compounds with a single electrophoresis instrument, a combination of different detection modes is required.
View Article and Find Full Text PDFCocaine (COC) is one of the most widely consumed illegal drugs around the world. Street COC is commonly adulterated with pharmaceutical compounds that mimic or intensify the COC's sensory effect. Adulteration is performed to increase the profit of criminal organizations and each one has their own way of doing it.
View Article and Find Full Text PDFSilver ions (Ag+) have been proposed as a biocide to treat the water in NASA's next generation of human space exploration vehicles/habitats. One advantage of Ag+ is that it is effective as a biocide in a range (200 to 500 ppb) safe for human consumption. So, monitoring Ag+ is essential to ensure the safety and health of the crew.
View Article and Find Full Text PDFThe determination of ethanol is one of the most important parameters in the fermentation industry, influencing not only the production yield and the quality of the product, but also its commercial value. In addition to the traditional approach based on distillation/density, procedure that is considered laborious and time-consuming, methods based on chromatography are widely used. Alternatives using electrochemical, spectroscopic and colorimetric techniques have been also proposed for alcohol analysis.
View Article and Find Full Text PDF1-propanol is a primary alcohol extensively used in the pharmaceutical, chemical, and food industries. It has been also found as a contaminant in the atmosphere and is considered a model compound to mimic the behavior and fate of aliphatic alcohols exposed to environmental conditions. In order to understand that role of relevant variables, this paper presents results obtained with a simple experimental set-up to investigate the reactivity of 1-propanol under mild oxidizing conditions.
View Article and Find Full Text PDFElectrophoresis
November 2018
The importance of microorganisms and biotechnology in space exploration and future planets colonization has been discussed in the literature. Meteorites are interesting samples to study microbe-mineral interaction focused on space exploration. The chemolithotropic bacterium Acidithiobacillus ferrooxidans has been used as model to understand the iron and sulfur oxidation.
View Article and Find Full Text PDFWith growing interest in exploring ocean worlds, such as Europa and Enceladus, there is a fundamental need to develop liquid-based analytical techniques capable of handling high salinity samples while performing both bulk and trace species measurements. In this context, CE with capacitively coupled contactless conductivity detection (CE-C D) has tremendous potential. One of its advantages is that this combination allows the detection of a wide number of charged species (both organic and inorganic) without the need of derivatization.
View Article and Find Full Text PDFAn EC-CE-C D flow system was applied to the investigation of electrocatalytic processes by monitoring carboxylic acids formed during the electro-oxidation at various potentials of primary alcohols (mixture of 1 mmol/L of ethanol, n-propanol, n-butanol and n-pentanol) in acidic, neutral and alkaline media. The electro-oxidation was carried out on gold and platinum disk electrodes (3 mm of diameter) in a thin-layer electrochemical flow cell. Products were sampled 50 μm apart from the electrode directly into the capillary.
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