Development of Online/Real-Time Gas Detection Method Based on Audio Frequency—Capacitively Coupled Plasma Chip

In this article, a custom design of capacitively coupled audio frequency plasma system is presented and tested for the purpose of performing gas detection and quantification. The main objective is to compensate for the use of bulky expensive analysis equipment with a simple cost-effective chip to be used in the laboratory and on site. The working principle relies on a gas molecule fragmentation via a jet plasma, toward production of base atoms and their detection/quantification through a spectrometric analysis. Upon constructing the system, argon and helium and mixtures of them were streamlined to the chip and the fragmented species were detected through an emission spectroscopy. An experimental plan was applied thoroughly, and hence, a database for each gas was generated aiming at identifying the most dominant peaks, which can be adopted as a fingerprint to detect the gas. Our results indicated that wavelengths in the near IR region at 763.5105 and 728.135 nm have recorded with highest intensity in the applied experimental domain for argon and helium, respectively. Based on that, a quantification for the gases in a mixture is also implemented successfully through an absorption spectroscopy technique. The resultant data have demonstrated a feasible approach with a detection limit of 0.011759 and 0.052 mol/L for argon and helium, respectively, which is accounted promising in line with the laboratory-on-chip principle. By combining efficiency with accessibility, this study introduces a novel approach that bridges the gap between high-performance analytical techniques and practical, real-world usability.