Characterization of ice-nucleating bacteria using on-line electron impact ionization aerosol mass spectrometry

2015 ◽  
Vol 50 (4) ◽  
pp. 662-671 ◽  
Author(s):  
R. Wolf ◽  
J. G. Slowik ◽  
C. Schaupp ◽  
P. Amato ◽  
H. Saathoff ◽  
...  
1979 ◽  
Vol 62 (6) ◽  
pp. 1274-1280
Author(s):  
George J Collins ◽  
Joseph D Rosen

Abstract A method for the analysis of T-2 toxin in milk is presented. Ethyl acetate extracts of milk samples which had been spiked with T-2 toxin were purified by thin layer chromatography and derivatized with N,O-bis(trimethylsilyl)acetamide to produce the T-2 toxin trimethylsilyl ether (T-2 toxin-TMS). N,O-bis(trimethylsilyl-d9)acetamide was used to make T-2 toxin d9-trimethylsilyl ether (T-2 toxin-d9TMS) which was added to the derivatized milk extract as an internal standard. Samples were analyzed by combined gas-liquid chromatography/mass spectrometry using either electron impact ionization or chemical ionization mass spectrometry. In electron impact ionization analyses, simultaneous monitoring of the T-2 toxin-TMS fragment ion at m/z 436 and the T-2 toxin-d9TMS fragment ion at m/z 445 gave a T-2 toxin-TMS detectability estimated at 6 μg/kg. In chemical ionization analyses, the T-2 toxin-TMS fragment ion at m/z 377 and the T-2 toxin-d9TMS fragment ion at m/z 386 were simultaneously monitored to give a T-2 toxin-TMS detectability estimated at 3 μg/kg. Average recovery was 85% at 200 μg/kg and 65% at 20 μg/kg.


1982 ◽  
Vol 35 (8) ◽  
pp. 1743 ◽  
Author(s):  
M Head ◽  
T McAllister

The mass spectra of ions of > 75 in an f.i.d.-type flame with benzene additive have shown that hitherto undetected species of formulas CllH9+ and CI3H9+ are present, which may be attributed to protonation of the biradicals C11H8 and C13H8 by H3O+. The remainder of the hydrocarbon ions present are attributable to protonation of aromatic compounds (e.g. naphthalene and indene) which have been detected previously in premixed benzeneloxygen flames by electron impact ionization. Addition of NH3 to the benzene sample suppresses all the hydrocarbon peaks of m/z > 100 but generates new peaks of m/z 80 and 94, attributable to the protonation of pyridine and aniline. Aniline may be generated by addition of NH2 radicals to benzene in the pyrolysis and reaction zones of the flame.


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