Field-deployed underwater mass spectrometers for investigations of transient chemical systems

• Published in: Talanta (Oxford) Vol. 64; no. 4; pp. 961 - 969
• Main Authors: Kibelka, Gottfried P.G., Timothy Short, R., Toler, Strawn K., Edkins, John E., Byrne, Robert H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2004; Oxford Elsevier
• Subjects: Analytical chemistry; Chemistry; Dissolved gases; Exact sciences and technology; General, instrumentation; Mass spectrometry; Membrane introduction; Spectrometric and optical methods; Volatile organic compounds; Volatile organic compounds; Membrane introduction; Dissolved gases; Mass spectrometry; Water; Hydrocarbon; In situ; Ultratrace compound; Instrumentation; Volatile organic compound; Analyzer; Remote sensing; Ion trap; Detection limit; Membrane
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2004.04.028

The mass spectrometer developments and underwater deployments described in this work are directed toward observations of important reactive and influential inorganic and organic chemicals. Mass spectrometer systems for measurement of dissolved gases and volatile hydrocarbons were created by coupling a membrane analyte-introduction system with linear quadrupole and ion trap mass analyzers. For molecular masses up to 100
amu, the in situ quadrupole system has detection limits on the order of 1–5
ppb. For masses up to approximately 300
amu, the underwater ion trap system detects many volatile hydrocarbons at concentrations below 1
ppb. Both instruments can function autonomously or via interactive communications from a remote control site. Continuous operations can be sustained for up to approximately 12 days. Deployments have initially involved shallow water proof-of-concept operations at depths less than 30
m. Future modifications are planned that will allow operational depths to 200
m.