Univariate and multivariate kinetic and structural analysis of photoinduced tetracycline degradation

AbstractTetracycline antibiotics found in waters worldwide pose a tremendous ecological and human health hazard due to bacterial resistances. Various processes are currently investigated to eliminate such anthropogenic micropollutants, among them advanced oxidation processes, where hydroxyl radicals cause disintegration of many organic substances. For mechanistic understanding and optimization for potential in-field use, kinetic descriptions and chemical reaction knowledge are important. Structural identification, quantitation and kinetic description of the substances are investigated via a univariate method, i.e. high-performance liquid-chromatography coupled with mass spectrometry and curve-fitting, and a multivariate method, i.e. absorption spectroscopy and curve resolution-alternating least squares fitting. The latter represented a fast, non-laborious analytical method. The univariate approach revealed four known and two new transformation products. First-order kinetics with follow-up reactions were observed. The univariate method yielded rate constants of about 0.33 min−1 for the degradation of both tetracyclines and distinct rate constants for transformation products, while rate constants of about 0.22 and 0.27 min−1 and an overall rate constant for non-identified transformation products were obtained from multivariate analysis due to the insufficient discriminatory power. Structural characterization, fast and easy kinetic parameter determination of photoinduced degradation may contribute to optimize advanced oxidation processes for the removal of antibiotics from waste water.Keywords: MCR-ALStetracyclineoxytetracyclineAOPskinetic determinationHPLC-HRMSDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Disclosure statementNo potential conflict of interest was reported by the authors.Availability of data and materialData can be obtained upon request from the corresponding author.