scholarly journals Combination of LC-MS2 and GC-MS as a Tool to Differentiate Oxidative Metabolites of Zearalenone with Different Chemical Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Andreas A. Hildebrand ◽  
Erika Pfeiffer ◽  
Georg Damm ◽  
Manfred Metzler

Recent studies on the mammalian and fungal metabolism of the mycotoxin zearalenone (ZEN) have disclosed the formation of six regioisomers of monohydroxy-ZEN and its reductive metabolite zearalenol (ZEL). Hydroxylation occurs at the aromatic ring or at one of four positions of the aliphatic macrocycle. In addition, an aliphatic ZEN epoxide, its hydrolysis product, and other products were identified in fungal cultures. In this paper, we report the product ion spectra of the [M-H]− ions of 22 oxidative metabolites of ZEN and ZEL, obtained by LC-MS2 analysis using a linear ion trap mass spectrometer with negative electrospray ionization. The MS2 spectra exhibit qualitative and quantitative differences which allow a clear distinction of most metabolites. Moreover, GC-MS analysis of the trimethylsilylated metabolites yields electron impact mass spectra with numerous fragment ions which can be used as fingerprint to confirm the chemical structure derived by LC-MS2 analysis.

1975 ◽  
Vol 53 (23) ◽  
pp. 3677-3680 ◽  
Author(s):  
Jean-Claude Richer ◽  
Philippe Lapointe ◽  
Martine Beljean ◽  
Michel Pays

Electron impact mass spectra are reported for the hydrazones of 3-methyl-2-benzothiazolinone (1), of 4-, 5-, 6-, and 7-chloro-3-methylbenzo-2-thiazolinones (2, 3, 4, and 5) and of 3-methyl-naphtho[2,1-d]-2-thiazolinone (6), as well as for 2-hydrazinobenzothiazole (7), for 4-, 5-, 6-, and 7-chloro-2-hydrazinobenzothiazoles (8, 9, 10, and 11) and for 2-hydrazinonaphtho[2,1-d]thiazole (12). The results obtained in the two series are compared. The 2-hydrazone and 3-methyl-benzo-2-thiazolinone and its derivatives all form a base peak corresponding to the molecular ion; fragmentation proceeds mainly by successive losses of·NH2, HCN, HCN, and then CS. Initial losses of N2H2, NH·, and NH3 are minor fragmentation routes.In the case of 2-hydrazinobenzothiazole and its derivatives, the base peak is still that of the molecular ion; however, the relative proportions of the various fragment ions vary with the position of sampling probe inside the apparatus. Thus it is concluded that the observed mass spectrum is that of a mixture of the possible hydrazone-hydrazine tautomers. The principal fragmentations involve the initial loss of NH3 (leading to a stabilized ion), of NH2· (probably from the hydrazone form), and of N2H2.(Journal Translation)


1976 ◽  
Vol 29 (2) ◽  
pp. 257 ◽  
Author(s):  
CG Macdonald ◽  
RL Martin ◽  
AF Masters

The progressive replacement by sulphur in the isostructural planar nickel compounds bis(2,2,6,6- tetramethylheptane-3,5-dionato)nickel(11) (1), bis(2,2,6,6-tetramethyl-5-thioxoheptan-3-onato)nickel(11) (2) and bis(2,2,6,6-tetramethylheptane-3,5-dithionato)nickel(11) (3) causes a change in their positive electron impact mass spectra from one dominated by metal-containing fragment ions (1) to one But 1 dominated by oxidized ligands (3). Comparisons are also made with the spectra of tris(monothio-dipivaloylmethanato)cobalt(111) and bis(1,l,1-trifluoro-4-thioxopentan-2-onato)nickel (11). Mass spectral peaks corresponding to mixed ligand species were observed when mixtures of (1) and (2) were vaporized in the mass spectrometer.


1988 ◽  
Vol 43 (12) ◽  
pp. 1151-1153 ◽  
Author(s):  
E. R. Rohwer ◽  
R.C. Beavis ◽  
C. Köster ◽  
J. Lindner ◽  
J. Grotemeyer ◽  
...  

A new ultra fast electron impact (El) ion source is pre­sented that produces a very short, high intensity electron beam, allowing medium resolution mass spectra to be re­corded without pulsing the ion accelerating voltages in a time-of-flight mass spectrometer (TOF-MS). The ion source requires minimum modification of any TOF-MS equipped with an electrostatic ion reflector and UV-laser. El-spectra are presented for comparison with literature spectra.


1981 ◽  
Vol 12 (29) ◽  
Author(s):  
M. A. ABOU-GHARBIA ◽  
D. T. TERWILLIGER ◽  
M. M. JOULLIE ◽  
R. M. SRIVASTAVA

1996 ◽  
Vol 2 (1) ◽  
pp. 129
Author(s):  
Teodor Balaban ◽  
Dietrich Müller

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