Analysis of a Reactive Dimethylenedihydrothiophene in Methylene Chloride by Low-Temperature Atmospheric Pressure Ionization Mass Spectrometry

Abstract

The use of atmospheric pressure ionization at -78 °C for the analysis of a thermally unstable compound, 2,5dimethylene-2,5-dihydrothiophene, dissolved in methylene chloride is demonstrated with a home-built lowtemperature electrospray source connected to a quadruple mass analyzer. To prevent the analyte molecule from polymerizing at elevated temperatures, the sample solution was maintained at -78 °C in the dry-ice-cooled sample injection and sample loop units. The solution was delivered to the spray needle by compressing the nitrogen gas in a syringe which was connected to the sample loop by a Teflon tube. At such low temperature, a strong ion signal was obtained from the analyte molecule as a result of corona discharge ionization.Electrospray ionization (ESI) mass spectrometry has been proven to be very useful for analyzing not only large biomolecules 1,2 but also small organic and inorganic compounds. [3][4][5][6][7] Since most organic and inorganic compounds do not dissolve well in water, organic solvents such as n-hexane, benzene, chloroform, methylene chloride, acetonitrile, and methanol are used alone or mixed together with water for the analysis of such compounds by ESI. [8][9][10][11][12][13][14][15] Most organic solvents freeze at temperatures far below 0 °C. For example, the melting point of methylene chloride (CH 2 -

Generating electrospray from solutions predeposited on a copper wire

“…copper ring). [17][18][19] The probe was mounted on a XY-translation stage and the tip of the copper ring was located approximately 1 cm in front of the ion sampling orifice of an atmospheric pressure ionization mass spectrometer (PE Sciex API 1). The electrospray on the copper ring was roughly coaxial with the ion sampling orifice.…”

Analysis of Polar Components in Crude Oil by Ambient Mass Spectrometry

“…For certain materials (e.g., synthetic polar polymers), the polar pyrolysates may contain useful diagnostic structural information (Williamson et al, 1980;Marshall et al, 1983;Shiea et al, 1996;Galipo et al, 1998). Unfortunately, during pyrolysis processes, many polar macromolecules are broken down to fragments that cannot be detected by GC/MS because they are retained in the pyrolysis zone, the injection system, or the capillary column owing to their high polarity or high molecular weight (Moss et al, 1980;Holzer et al, 1989).…”

Development and Application of a Brush-Spray Derived from a Calligraphy-Brush-Style Synthetic Hair Pen for Use in ESI/MS

“…Among these methods, ambient ionization mass spectrometry is in widespread use, because it is quite simple and straightforward and also increases the speed of a mass-spectrum analysis. [1][2][3][4][5][6][7][8][9][10][11] Furthermore, since the development of ambient ionization mass spectrometry, socalled paper spray-mass spectrometry (PS-MS) has opened new insights in the eld of mass spectrometric analysis and, since its debut on 2010, it has now become a quite popular and important method for use in mass spectrometry. 12) us far, PS-MS has been applied successfully in many areas of research, including food science, 13) the analysis of protein complexes, 14,15) bio uid samples, 16,17) the online chemical monitoring of cell cultures, 18) rapid discrimination of bacteria, 19) and drugs of abuse in whole blood or saliva, [20][21][22] and even in an ambient organic analysis.…”