Degradation kinetics of the Alternaria mycotoxin tenuazonic acid in aqueous solutions.
The degradation kinetics of the Alternaria mycotoxin tenuazonic acid (l-TA) in aqueous buffer were studied over a period of 4 months at different pH levels (3.5 and 7.0) and temperatures (4, 25 and 40 degrees C). l-TA and its degradation products were quantified by newly developed high-performance liquid chromatography methods with UV or electrospray multistage mass spectrometry detection. At pH 3.5, significant degradation occurred at 25 and 40 degrees C, the respective l-TA half-lives being 73.8 +/- 0.4 and 14.0 +/- 0.1 days. Two degradation processes, epimerization and hydrolysis, were evaluated kinetically. The hydrolytically formed iso-deacetyl TA (iso-DTA, epimeric mixture) was found to be the stable end product of l-TA degradation under the conditions of this study. This indicates that iso-DTA as well as the l-TA epimer u-TA are formed in aqueous beverage matrices.
Siegel
David
D
Division I.2, Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489, Berlin, Germany. david.siegel@chemie.hu-berlin.de
Merkel
Stefan
S
Bremser
Wolfram
W
Koch
Matthias
M
Nehls
Irene
I
D000528:Alternaria / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007536:Isomerism; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013696:Temperature; D013720:Tenuazonic Acid / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D014867:Water; D013720:Tenuazonic Acid