The most affordable option for moisture analysis by gas chromatography
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APPLICATION NOTE GC METHOD FOR MOISTURE ANALYSIS USING ARGON CARRIER AND DISCHARGE GAS The most affordable option for moisture analysis by gas chromatography Date: April 2023 Authors: Marc-Antoine Langevin, Ph.D. André Lamontagne, Ing. Yves Gamache, CEO, CTO

ABSTRACT Nitrogen, hydrogen, oxygen and carbon dioxide samples containing trace-level moisture were generated and analyzed using a miniMOv GC platform equipped with a detector based on the Enhanced Plasma Discharge (Epd) technology configured in H2O selective mode. This detection technology allows the use of argon instead of costly helium as the carrier and discharge gas. The method developed with this system was demonstrated to be reliable and highly sensitive for reallife application with various permanent gas matrices containing trace-level moisture. A limit of detection (LOD) in the...

patented many new technologies that are making this measurement possible and reliable. Indeed, the level of sensitivity mostly depends on the detector used, but the reliability of the method also depends on a combination of all the technologies used for the analysis. In 2017, ASDevices released the SePdd, based on Enhanced Plasma Discharge (Epd) detection technology. This technology measures light emitted at specific wavelengths by analytes in a stabilized argon, nitrogen or helium plasma using a highly sensitive photodiode and optical filters. To further stabilize the plasma and obtain...

Purged Lip Sealing Valve Technologypatent-pending The Purged Lip Sealing Valve (PLSV) is a unique valve technology developed by ASDevices, which offers many advantages over the other chromatographic valve technologies [8-10]. For moisture analysis, it is important to treat the valve head with an inert treatment, since water sticks to stainless-steel surfaces. Due to the sealing force required in typical conical rotary valves, such treatment cannot be used, as it would cause treatment peeling after only a few actuations. With the PLSV technology, thanks to its reduced surface sealing area...

A Watercol 1910 30m x 0.25mm x 0.2µm film thickness (Supelco) was used to separate moisture from the matrix. Argon was purified using ASDevices’ Pure purifier, which removes trace of permanent gases and moisture down to 1 ppb. The carrier gas pressure in front of the column was set to 35 psi. Due to the low carrier gas flow through the column, 25 mL/min argon make up gas was also added to the detector. The SePdd was connected to a vacuum pump to improve the peak shape. Since hydrogen has a strong tendency to stick to the column material, the temperature was ramped from 40°C to 80°C at a...

The chromatograms also showed a good linearity with a R2 of 0.999 for the moisture response as a function of concentration. From the results acquired, a LOD of 0.1 ppm was also calculated here. Figure 8 – Calculated concentration for a sample containing moisture in Nitrogen over one hour Trace-level Moisture in O2 and CO2 Preliminary results were also acquired for moisture in O2 and in CO2. The chromatograms acquired are presented in Figure 11 and Figure 12 respectively. Then, a sample containing 30 ppm H2O in hydrogen was generated and analyzed with the miniMOv GC platform. The result is...

a proprietary trapping material for moisture preconcentration and the T&R PLSV, unique to ASDevices. This system is schematically represented in Figure 13. Figure 13- Schematic representation of the T&R PLSV in sampling position, used for moisture preconcentration. In this representation, a GC column is used, which might be needed for the analysis of complex matrices. However, for the analysis of simple matrices such as the permanent gases, moisture can be preconcentrated on our proprietary trapping material, while the matrix is eliminated thanks to the trap’s purge position. Moisture can...

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