title: Identification of antimycotic drugs transformation products upon UV exposure.
abstract: The reactivity of three imidazolic, environmental persistent antimycotic drugs (clotrimazole, CTZ; ketoconazole, KTZ; and miconazole, MCZ) upon exposure to ultraviolet (UV) radiation is discussed. First, precursor compounds were immobilized in a silicone support which was further exposed to UV light at two different wavelengths: 254 and 365 nm. After solvent desorption, degradation kinetics of the precursor pharmaceuticals, identification of the arising transformation products (TPs) and evaluation of their time-course were investigated by liquid chromatography (LC) with quadrupole time-of-flight (QTOF) mass spectrometry (MS) detection. The three antimycotics displayed similar stabilities when exposed to 254 nm light; however, CTZ was significantly more stable than MCZ and KTZ when irradiated with the 365 nm lamp. TPs identified in silicone supports resulted from de-chlorination, cleavage, intra-molecular cyclization and hydroxylation reactions. Many of these species were also detected when exposing other solid matrices, such as sand and agricultural soil, previously spiked with target compounds, to UV light. The 50% estimated lethal concentration, calculated using the 48-h Daphnia magna test, for the two main TPs of CTZ and MCZ, at both wavelengths, were lower than those corresponding to the precursor drugs.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario (IIAA), Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Casado
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario (IIAA), Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain. Electronic address: isaac.rodriguez@usc.es.
authors.forename: Isaac
authors.initials: I
authors.lastname: Rodríguez
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario (IIAA), Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Ramil
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario (IIAA), Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cela
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry* / Q000528:radiation effects* / Q000633:toxicity; D003022:Clotrimazole / Q000737:chemistry; D003621:Daphnia; D004350:Drug Residues / Q000633:toxicity; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity; D007654:Ketoconazole / Q000737:chemistry; D008825:Miconazole / Q000032:analysis; D012015:Reference Standards; D012997:Solvents; D014466:Ultraviolet Rays
chemical_list: D000935:Antifungal Agents; D004785:Environmental Pollutants; D012997:Solvents; D008825:Miconazole; D003022:Clotrimazole; D007654:Ketoconazole
keywords: Antimycotic drugs; Liquid chromatography–quadrupole time of flight mass spectrometry; Transformation products; UV degradation