Tool for removal of ion source flange on the LKB 9000 gas chromatograph mass spectrometer

1979 ◽  
Vol 6 (9) ◽  
pp. 414-414
Author(s):  
Daniel R. Knapp
Keyword(s):  
Mass Spectrometer ◽  
Ion Source ◽  
Gas Chromatograph

Evaluation of a benchtop capillary gas chromatograph-mass spectrometer for clinical toxicology.

1985 ◽  
Vol 31 (5) ◽  
pp. 741-746 ◽  
Author(s):  
D G Deutsch ◽  
R J Bergert
Keyword(s):  
Mass Spectrometer ◽  
Clinical Laboratory ◽  
Ion Source ◽  
Clinical Toxicology ◽  
Gas Chromatograph ◽  
Degree Of Confidence ◽  
Routine Clinical Laboratory ◽  
High Degree ◽  
Drug Reference

Abstract We evaluated the Hewlett-Packard 5995B benchtop capillary gas chromatograph-mass spectrometer (GC-MS) for its ability to identify drugs commonly detected and (or) measured in the clinical toxicology laboratory. Initial experiments indicated that the instrument as originally configured, with an isolation valve between the gas chromatograph and mass spectrometer, was unsatisfactory for the identification of hypnotics-sedatives. However, with the capillary inserted directly into the ion source, we could detect 10 ng of these drugs on a total-ion chromatogram. The software programs cause the instrument to be highly automated. In terms of ease of operation and speed it was found suitable for use in a routine clinical laboratory. Chromatography of urine extracts on the capillary gas chromatograph-mass spectrometer yielded excellent resolution of parent compounds and metabolites (e.g., diphenhydramine together with approximately four metabolites and propoxyphene with four metabolites). However, the manufacturer's computer program used to evaluate the quality of the match between the experimental mass spectra and the 375 drug reference spectra was only moderately successful in identifying unknown compounds. The ability of this capillary GC-MS to identify most compounds with a high degree of confidence will be increased by enlarging the library to include more drugs and metabolites and by using a more reliable computerized matching program.

Integrated gas chromatography-mass spectrometry

1973 ◽  
Vol 6 (3) ◽  
pp. 311-335 ◽  
Author(s):  
Ragnar Ryhage
Keyword(s):  
Molecular Weight ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Packed Column ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometric Analysis ◽  
Gas Chromatograph ◽  
Continuous Increase

Mass spectrometric analysis of organic compounds was in the early 1950s done mostly for quantitative determination of petroleum products. The use of the mass spectrometer for qualitative analysis of solid organic material samples was shown by O'Neil & Wier (1951) and since then a continuous increase in mass spectrometric studies of different classes of organic compounds has been noted. After the gas chromatograph was developed by James & Martin (1952) the quantitative analysis of complex mixtures of organic compounds was possible and after a few years the gas chromatographic method was considered as routine. The first connection of a gas chromatograph (GC) to a mass spectrometer (MS) was made by Holmes & Morell (1957). They studied gases using a splitter system where only a small part or less than 1% of the effluent from a packed column was transferred to the ion source of the mass spectrometer. The next step in GC—MS development was made by Gohlke (1959), who studied compounds of low molecular weight using capillary column directly connected to a time-of-flight mass spectrometer. This was possible due to the fact that the carrier gas flow rate could be limited to about 1 ml/min. To avoid the sample loss resulting from using a packed column with the splitter system a jet molecular separator was constructed as an interphase between the packed column and a mass spectrometer with magnetic sector analyser (Ryhage, 1964). Mixtures of fatty acids and of hydrocarbons with a molecular weight of up to about 420 were studied. In this study spectra were taken at irregular intervals.

scholarly journals Interaction of Fullerenes with Organosilanes in the Ionization Chamber of a Mass Spectrometer under Electron Impact and the Reaction of C60with Tetraphenylsilane in Solution under UV Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Yury I. Lyakhovetsky ◽  
Elena A. Shilova ◽  
Alexandra P. Pleshkova ◽  
Alexander I. Belokon ◽  
Sergey O. Yakushin ◽  
...  
Keyword(s):  
Electron Impact ◽  
Mass Spectrometer ◽  
Uv Irradiation ◽  
Ionization Chamber ◽  
Ion Source ◽  
Organic Radicals ◽  
Mechanistic Study ◽  
Mass Spectral ◽  
Additional Support ◽  
Derivatives Of

C60was shown to react with organosilanes Me4Si, Ph2SiH2, Ph2MeSiH, Ph4Si, andα-naphthylphenylmethylsilane in the electron ionization ion source of a mass spectrometer with the transfer of the corresponding organic radicals (Me, Ph, andα-naphthyl) from the silanes to the fullerene. The reactions were accompanied by hydrogen addition to some products and hydrogen loss from them. C70reacted with Me4Si analogously. A reaction mechanism involving homolytic dissociation of the silanes under electron impact to the corresponding organic radicals, which react further with C60at the surface of the ionization chamber of the mass spectrometer to give the respective adducts, was offered. A mechanistic study of the reaction of C60with Me4Si supported it. No silicon containing derivatives of the fullerenes were found. C60reacted with Ph4Si in solution under UV irradiation in a similar fashion furnishing phenyl derivatives of the fullerene. These results provide an additional support to the hypothesis formulated earlier thatthe homolytic reactive mass spectrometry of fullerenes (the reactions of fullerenes with other species in the ionization chambers of mass spectrometers and their mass spectral monitoring)can predict the reactivity of them toward the same reagents in solution to a significant extent.

Sign in / Sign up

Export Citation Format

Share Document