Online Detection of Volatile Organic Compounds in Air at Parts-per-Trillion Levels by Membrane Introduction Mass Spectrometry

Proton affinity of peroxyacetyl nitrate sampled by membrane introduction mass spectrometry

“…27 Since then, this area has grown [28][29][30] and MIMS has also been applied to such important areas such as biological waste water treatment, 31 chemical reaction monitoring, 32,33 bioreactor monitoring [34][35][36][37][38] and especially to the analysis of volatile and semi-volatile organic compounds. 29,[39][40][41] Key to recent developments in MIMS has been the use of flow injection methods of sample handling 42,43 in which the solution is transported over the surface of the membrane, often located in a direct insertion membrane probe in the ion source. MIMS is particularly useful for ambient air sampling since it avoids the need for pre-concentration and yet allows separation of analytes from water vapor.…”

Membrane Inlet-based Portable Time-of-flight Mass Spectrometer for Analysis of Air Samples

“…These wide dynamic ranges are in good agreement with the dynamic ranges measured for other VOCs in earlier studies. 32,33 In order to determine the basic membrane parameters, the time dependence of the signal from the mass spectrometer was investigated. The sample modulation was controlled with an alternating valve that switches between the sample stream and the background stream.…”

Real-Time Broad Spectrum Characterization of Waste by Membrane Introduction Mass Spectrometry

“…Most strikingly, detection limits for VOCs are in the low parts-per-trillion range. In fact, in favorable cases, the detection of parts-per-quadrillion levels of VOCs in water [5] and the detection of 20 parts-per-trillion by volume in air [6] have been demonstrated. Because the nonporous silicone membrane excludes particulates and ionic compounds, including the salts found in seawater, the technique offers a way to measure trace levels of organics in a complex aqueous matrix.…”