Membrane inlet

P. M. Vignais, L. Coumac, E. C. Hatchikian, S. Elsen, L. Serebryakova, N. A. Zorin, B. Dimon (2002) Continuous monitoring of the activation and activity of [NiFe]-hydrogenase by membrane-inlet mass spectrometry. Int. J. HydrogenEner., 27 1449-1461... 

P. D. Tortell. Dissolved Gas Measurements in Oceanic Waters Made by Membrane Inlet Mass Spectrometry. Limnol. Oceanogr. Methods, 3(2005) 24-37. 

Of the isotopes of hydrogen, deuterium can be detected by mass spectrometric analysis of masses 2, 3 and 4 nsing a membrane-inlet mass spectrometer (Fig. 5.4). 

Kristensen GH, Klausen MM, Hansen VA, Lauritsen FR (2010) On-line monitoring of the dynamics of trihalomethane concentrations in a warm public swimming pool using an unsupervised membrane inlet mass spectrometry system with off-site real-time surveillance. Rapid Commun Mass Spectrom 24(l) 30-34... 

Greaser, C. S. Lamarca, D. G. Brum, J. Werner, C. New, A. P dos Santos, L. M. E. Reversed-Phase Membrane Inlet Mass Spectrometry Applied to the Real-Time Monitoring of Low Molecular Weight Alcohols in Chloroform. Anal. Chem. 2002, 74, 300-304. 

An extensive and detailed coverage of the MS of expls in general has been documented (Ref 163). Volatile constituents of Comp A-3, Comp B, pressed TNT and cast TNT were surveyed with a residual gas analyzer MS (Ref 40). The mass spectra of all possible TNT (except for 3,4,5-TNT) and DNT isomers in the vapor phase were obtained as a function of ionizing voltage (Refs 65 84). The use of membrane inlet systems for the separation of TNT vapor in trace vapor detection is described and an analysis of the membrane inlet system for quadrupole mass spectroscopy is presented (Refs 95 113). Estimations of the vapor pressure of TNT were made mass spectrometrically in the range of 50—... 

Nonporous polymeric membranes have been incorporated as sample inlets in mass spectrometry (MS) for the direct sampling of volatile and semivolatile organic compounds (VOCs and SVOCs). The technique of membrane inlet (introduction) mass spectrometry (MIMS) has achieved tremendous success in the last two decades in terms of instrumentation and applications. Figure 4.1 depicts the experimental setup of (i) in-sample membrane MIMS and (ii) direct insertion (near the ion source in MS) membrane MIMS. 

MIMS membrane inlet (introduction) mass spectrometry... 

Creaser, C.S., D.J. Weston, and B. Smith. 2000. In-membrane preconcentration/membrane inlet mass spectrometry of volatile and semivolatile organic compounds. Anal. Chem. 72 2730-2736. 

Membrane SLM MESI MMLLE MIMS PME HF-LPME MASE LGLME Headspace-solid phase dynamic extraction (HS-SPDE) Purge-and-membrane extraction Headspace/membrane extraction w. sorbent interface (HS-MESI) Headspace/membrane inlet mass spectrometry (HS-MIMS)... 

Ojala, M., R. Ketola, T. Mansikka, et al. 1997. Detection of volatile organic sulfur compounds in water by headspace gas chromatography and membrane inlet mass spectrometry. HRC—J. High Res. Chromatogr. 20 165-169. 

Dosage of analytes into a mass spectrometer Membrane inlet 1 Mass Spectrometry -MMS)... 

The principles, sampling systems, control of the measuring device and application of MS for bioprocesses have been summarized by Heinzle [157,158] and Heinzle and Reuss [162]. Samples are introduced into a vacuum (< 10 5 bar) via a capillary (heated, stainless steel or fused silica, 0.3 x 1000 mm or longer) or a direct membrane inlet, for example, silicon or Teflon [72,412]. Electron impact ionization with high energy (approx. 70 eV) causes (undesired) extensive fragmentation but is commonly applied. Mass separation can be obtained either by quadrupole or magnetic instruments and the detection should be performed by (fast and sensitive) secondary electron multipliers rather than (slower and less sensitive) Faraday cups (Fig. 21). 

Capillary inlet MS is the scientific exception [52] but it is routinely applied even in industry most scientific publications report on membrane inlet applications. Almost all volatile substances can be analyzed from the gas phase using capillary inlet MS provided their partial pressure in the exhaust gas is > 1 pbar [313]. Software is necessary but is available only for a few special cases [291]. 

An important problem with membrane inlet systems is quantification because the membrane behavior is more or less unpredictable [138, 352] however, the membrane inlet can be even more rapid [56,57]. 

Whilst on-line desorption chemical ionisation mass spectrometry (MS) has been used to analyse fermentation biosuspensions for flavones [11], the majority of MS applications during fermentations have been for the analysis of gases and volatiles produced over the reactor [12-15], or by employing a membrane inlet probe for volatile compounds dissolved in the biosuspensions [16-22]. It is obvious that more worthwhile information would be gained by measuring the non-volatile components of fermentation biosuspensions, particularly when the product itself is non-volatile, which is usually the case. 

Kotiaho, T., Gylling, S., Lunding, A. and Lauritsen, F.R. (1995) Direct determination of styrene and tetrachloroethylene in olive oil by membrane inlet mass spectrometry. J. Agric. Food Chem., 43, 928-930. 

Viktorova, O.S., Kogan, V.T., Manninen, S.A., Kotiaho, T., Ketola, R.A., Dubenskii, B.M., Parinov, S.P., Smirnov, O.V. Utilization of a multimembrane inlet and a cyclic sudden sampling introduction mode in membrane inlet mass spectrometry. J. Am. Soc. Mass Spectrom. 15, 823-831 (2004)... 

Li, X., Xia, L., Yan, X. Application of membrane inlet mass spectrometry to directly quantify denitrification in flooded rice paddy soil. Biol. Fertil. Soils 50, 891-900 (2014)... 

Beckmann, K., Messinger, J., Badger, M.R., Wydrzynski, T., Hillier, W. On-line mass spectrometry membrane inlet sampling. Photosynth. Res. 102, 511-522 (2009)... 

TorteU, P. D. (2005). Dissolved gas measurements in oceanic waters made by membrane inlet mass spectrometry. Limnol. Oceanogr. Methods 3, 24—37. 

ARA, acetylene reduction activity MIMS, membrane inlet mass spectrometry. 

MEVIS/IPM, membrane inlet mass spectrometry/isotope pairing method TCD, gas chromatography-thermal conductivity detector AIT, acetylene inhibition technique IPM, isotope pairing method with isotope ratio mass spectrometry MIMS, membrane inlet mass spectrometry Stoichiometery, benthic flux DICiDIN stoichiometry MIMS + N03, membrane inlet mass with N03 amendment 15N2 production, 15N03 or 15NH4 conversion to 15N2. 

An, S., Gardner, W., and Kana, T. (2001). Simultaneous measurement of denitrification and nitrogen fixation using isotope pairing with membrane inlet mass spectrometry analysis. Appl. Environ. Microbiol. 67, 1171-1178. 

Harmett, H. E., and Seitzinger, S. P. (2003). High-resolution nitrogen gas profiles in sediment porewaters using a new probe for membrane-inlet mass spectrometry (MIMS). Mar. Chem. 83, 23-30. 

Kana, T. M., Darkangelo, C., Hunt, M. D., Oldham, J. B., Bennett, G. E., and CornweU, J. C. (1994). Membrane inlet mass spectrometer for rapid high-precision determination of N2, O2 and Ar in environmental water samples. Anal. Chem. 66, 4166—4170. 

The newest approach to measuring denitrification uses a mass spectrometer that can rapidly measure the N2/Ar ratio in water using membrane inlet mass spectrometry (MIMS, Kana et al., 1994, 1998). In this approach, sediment cores are incubated under continuous flow conditions. The N2/Ar ratio is then measured at the inlet and outlet of the core over time. Advantages of the technique are the short incubation times needed (usually less than 12 h), and the high throughput and small sample size ( 5 ml) of MIMS analysis. 

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