Membrane introduction mass spectrometry

Bauer S, Solyom D. 1994. Determination of volatile organic compoimds at the parts per trillion level in complex aqueous matrices using membrane introduction mass spectrometry. Anal Chem 66(24) 4422-4431. 

Liquid membrane enrichment coupled to mass spectrometry. Membrane introduction mass spectrometry (MIMS) is an established method of sample... 

Levels observed were up to 500 x greater than the level (0.7 ng/L) associated with a one in a million lifetime cancer risk. Volatile DBFs, such as trichloramine, dichloromethylamine, and dichloroacetonitrile, have also been measured in pool waters using membrane introduction mass spectrometry (MIMS) [133]. Brominated DBFs from sunscreens have been reported [136], as have DBFs from the reaction of chlorine with parabens used in lotions, cosmetics, and sunscreens [117]. 

Riter LS, Charles L, Turowski M, Cooks RG (2001) External interface for trap-and-release membrane introduction mass spectrometry applied to the detection of inorganic chloramines and chlorobenzenes in water. Rapid Commun Mass Spectrom 15 2290-2295... 

Rios RVRA, Da Rocha LL, Vieira TG, Lago RM, Augusti R (2000) On-line monitoring by membrane introduction mass spectrometry of chlorination of organics in water. Mechanistic and kinetic aspects of chloroform formation. J Mass Spectrom 35(5) 618-624... 

Mendes, M.A. and M.N. Eberlin. 2000. Trace level analysis of VOCs and semi-VOCs in aqueous solution using a direct insertion membrane probe and trap and release membrane introduction mass spectrometry. Analyst 125 21-24. 

Thompson, A.J., A.S. Creba, R.M. Ferguson, E.T. Krogh, and C.G. Gill. 2006. A coaxially heated membrane introduction mass spectrometry interface for the rapid and sensitive on-line measurement of volatile and semi-volatile organic contaminants in air and water at parts-per-trillion levels. Rapid Commun. Mass Spectrom. 20 2000-2008. 

Ketola, R.A., T. Kotiaho, M.E. Cisper, and T.M. Allen. 2002. Environmental applications of membrane introduction mass spectrometry. J. Mass Spectrom. 37 457 -76. 

In an attempt to overcome the significant difficulties that the presence of water vapor poses to the analysis of very volatile compounds, purge-and-membrane extraction techniques have been developed that largely prevent the introduction of water into the analytical system. Typical implementations of this form of sample introduction have been called by its developers membrane extraction with a sorbent interface (MESI),97 or membrane introduction mass spectrometry (MIMS).98 " They are based on a silicone hollow-fiber membrane that is inserted into the sample to be monitored, and the passing of a certain volume of inert gas through the membrane. Volatile compounds permeate the membrane and are swept to the adsorbent trap from which they are desorbed into the GC. This method of sample introduction is particularly suited for field and process monitoring and for dirty samples, since it prevents any nonvolatile compounds from entering the analytical system.100... 

The use of membrane introduction mass spectrometry (MIMS) was first reported in 1963 by Hoch and Kok for measuring oxygen and carbon dioxide in the kinetic studies of photosynthesis [46], The membrane module used in this work was a flat membrane fitted on the tip of a probe and was operated in the MIS mode. The permeated anaytes were drawn by the vacuum in the MS through a long transfer line. Similar devices were later used for the analysis of organic compounds in blood [47], Memory effects and poor reproducibility plagued these earlier systems. In 1974, the use of hollow-fiber membranes in MIMS was reported, which was also operated in the MIS mode [48], Lower detection limits were achieved thanks to the larger surface area provided by hollow fibers. However, memory effects caused by analyte condensation on the wall of the vacuum transfer line remained a problem. 

Mass-analysed Ion Kinetic Energy Spectrometry Membrane Introduction Mass Spectrometry Multiphoton Ionization Multiphoton Dissociation... 

A consequence of MESI application is the membrane introduction mass spectrometry system (MIMS), which allows selective extraction of VOCs and direct MS analysis without chromatographic separation. The gaseous substances permeate through the highly hydrophobic membrane and are introduced directly to a mass spectrometer [115-118]. 

Another MS technique used in connection to pyrolysis is MIMS (membrane introduction mass spectrometry). MIMS is in fact a special inlet for the mass spectrometer, where a membrane (usually silicone, non-polar) lets only certain molecule types enter the Ionization chamber of the MS. This allows, for example, direct analysis of certain volatile organic compounds from air. The system makes possible the coupling of atmospheric pyrolysis to a mass spectrometer [61a] allowing direct sampling of the pyrolysate. Other parts of the mass spectrometer do not need to be changed when using MIMS. 

Other Fission Processes - The results of the irradiation of benzyl acetate and 3,5-dimethoxybenzyl acetate have been analysed using membrane introduction mass-spectrometry. Irradiation of the acid derivative (136) under nitrogen in methanol brings about the formation of the corresponding ester. The authors suggest that this process is the result of CO bond fission and the liberation of a hydroxy radical. Subsequently this is trapped by methanol as the ester (137). 

Soni, M.H., J.H. Callahan, and S.W. McElvany. 1998. Laser desorption-membrane introduction mass spectrometry. Anal. Chem. 70 3103-3113. 

The concept of combinatorial screening can be further divided into two subsystems, focus level screening and discovery screening [2]. While the focus system provides more detailed information such as kinetics and selectivity on many catalyst samples per test, a discovery system can screen thousands of catalytic materials with sufficient resolution to identify promising hits. An example of a discovery assay for reactivity testing that has been successfully implemented at UOP LLC is the laser activated membrane introduction mass spectrometry (LAMIMS) system [2, 3]. 

Johnson, R.C. Siinivasan, N. Cooks, R.G. Schell, D., Membrane introduction mass spectrometry in pilot plant on-line monitoring of fermentation broths. Rapid Commm. Mass Spectmm. 1997, 11, 363. 

Kotiaho, T. Lauiitsen, F.R. Choudhury, T.K. Cooks, R.G. Tsao, G.T. Membrane introduction mass spectrometry AwaZ. Chem. 1991, 63, 875A-883A. 

Soni, M. Bauer, S. Amy, J.W. Wong, R Cooks, R.G. Direct determination of organic compounds in water at parts-per-quadrillion levels by membrane introduction mass spectrometry. Anal. Chem. 1995, 67,1409-1412. 

Mendes, M.A. Pimpim, R.S. Kotiaho, T. Eberlin, M.N. A cryotrap membrane introduction mass spectrometry system for analysis of volatile organic compounds in water at the low parts-per-triflion level. Anal. Chem. 1996,68, 3502-3506. 

Bocchini, R Rozzi, R. Andalo, C. Galletti G.C. Experimental upgrades of membrane introduction mass spectrometry for water and air analysis. Anal Chem. 2001, 16, 3824-3827. 

The need for maximum sample throughput and minimal human interaction within analytical procedures has provided considerable impetus to the development of integrated systems. SPE-LC in-tube SPME followed by ultraviolet (UV) or MS detection and membrane introduction mass spectrometry (MIMS) have both been used to this end. Submersible MIMS systems capable of extended underwater deployment down to 200 m and with a mass range of up to 200 amu have recently come onto the market. Elow injection coupled with MIMS allows fast, near-real-time determination of, for example, phenols in water. Derivatization of the phenols with acetic anhydride can be used to enhance both the selectivity and sensitivity of this method. Other online derivatization procedures are under development with a view to increasing the scope for rapid determination of highly polar compounds that have previously proved difficult to analyze. Large volume injection techniques and developments in enzyme-linked immunosorbent assay (ELISA) technologies... 

Nogueira, R.F.P., Alberici, R.M., Mendes, M.A., Jardim, W.E., Eberlin, M.N. (1999) Photocatalytic Degradation of Phenol and Trichloroethylene On-line and Real-time Monitoring via Membrane Introduction Mass Spectrometry. Ind. Eng. Chem. Res. 38 1754-1758. 

Kotiaho, T Lister, A.K., Hayward, M.J., Cooks, R.G. (1991) On-line Monitoring of Chloramine Reactions by Membrane Introduction Mass Spectrometry. Talanta 38 195-200. 

Rios, R.V.R.A., da Rocha, L.L., Vieira, T.G., Lago, R.M., Augusti, R. (2000) Online Monitoring by Membrane Introduction Mass Spectrometry of Chlorination of Organics in Water. Mechanistic and Kinetic Aspects of Chloroform Formation. J. Mass Spectrom. 35 618-624. 

---