Trace detection of natural gas leakage using novel hollow-electrode radiofrequency glow discharge ion-source mass spectrometry

Abstract

Natural gas has become an indispensable energy source for people's lives, but natural gas leakage brings great harm to people's health and property as well as the atmospheric environment. The current ion source cannot meet the requirements of trace natural gas leakage detection due to the interference of air when the sample is injected at atmospheric pressure, and the whole detection process is time-consuming, so rapid on-line detection is not possible. In this paper, a novel hollow electrode radio frequency glow discharge ion source is designed for direct injection of samples at atmospheric pressure. The ionization efficiency of the ion source can be greatly improved by applying a 13.56 MHz radio frequency power supply, and trace natural gas can still be detected rapidly even under air interference. The ion source coupled quadrupole mass spectrometer can detect CH₃⁺, C₂H₃⁺, C₃H₈⁺, and [C₄H₈S + H]⁺ to achieve the detection of methane, ethane, propane, and tetrahydrothiophene. The limit of detection of 0.01 mg m⁻³ for methane, 0.0026 mg m⁻³ for ethane, 0.0077 mg m⁻³ for propane, and 0.013 mg m⁻³ for tetrahydrothiophene, along with an RSD of 1.5–5.8%, can meet the criteria for trace natural gas leak detection. The designed novel ion source provides a fast and accurate detection tool for trace natural gas leak detection.