Development of a portable “brick” mass spectrometer for volatile organic compounds analysis

Volatile organic compounds (VOCs) are critical indicators of air pollution, necessitating rapid detection for public and environmental safety. This study presents an enhanced portable "brick" mass spectrometer with a single ultraviolet photoionization source (SPI-BMS) for VOC analysis. By implementing a reengineered continuous atmospheric pressure interface and optimizing the vacuum architecture, the total instrument mass was reduced to approximately 8 kg. We systematically investigated key parameters (e.g., pump configuration, capillary geometry), revealing their direct impact on sensitivity, stability, and resolution. After optimization, the SPI-BMS achieves unit mass resolution and relatively rapid responses. In the basic configuration, the system achieved a detection limit of 8.9 ppbv for methyl methacrylate, which was further improved to 3.7 ppbv with the addition of an auxiliary diaphragm pump. The SPI-BMS balances portability and analytical performance, making it a powerful tool for sensitive on-site detection of VOCs.