New generation underwater mass spectrometers for dissolved gases and volatile organic compound detection and in situ monitoring in the oceans

Pacific Environmental Technologies, LLC (Pace Tech) in collaboration with Brooks Automation and the University of Hawaii has developed a suite of compact mass spectrometer-based instruments for multi-species determination of dissolved gases and volatile organic compounds that can function autonomously or semi-autonomously in a range of water depths. Pace Tech offers two high-vacuum pumping options and two high-pressure membrane introduction mass spectrometry (MIMS) approaches. System power is under 30 to 60 Watts, depending upon the high-vacuum pumping option selected. A shallow-water version is human-rated to operational depths of >;1000 m, with a deep-water version human-rated to >;4000 m water depth. Using a new ion trap mass spectrometer, full mass spectra take 100 milliseconds (ms) to capture, with spectrum averaging used to increase signal-to-noise and lower detection limits. Several design changes were made to improve the sensitivity of the prototype´s membrane introduction sample inlet, with additional improvements made to the system operating software for client use. We are also providing a lower-power NEG-ion pumped vacuum system to achieve overall system power reduction to fewer than 30 Watts.