Bisphenol A, bisphenol S, and fluconazole are ubiquitous environmental pollutants and their removal from water is of utmost importance. As the biodegradation of these compounds is usually not enough effective, often other degradation methods are required. The study presents the difference between biodegradation and photo-Fenton degradation with a much higher efficiency obtained in the latter process. Levels of biodegradation and chemical degradation were assessed based on high-performance liquid chromatography determination. Optimization of the photo-Fenton removal of bisphenol A, bisphenol S, and fluconazole resulted in about 100 % primary degradation of both bisphenols during 10-20 min and almost 90 % primary degradation of fluconazole within an hour. Degradation products formed in the process were identified using liquid chromatography with mass spectrometry and showed central scission of bisphenol S with the formation of phenol and sulfuric acid while for bisphenol A and fluconazole the oxidation resulted in much smaller structural changes.
13 March 2025 in Journal of Environmental Management
Yerba mate beverage is prepared from Ilex paraguariensis grown in South America, and its popularity still is increasing. The aim of this study was to show the differences in the content of antioxidant compounds between hot- and cold-prepared mate beverages. The antioxidant capacity of the infusions was tested using the Folin–Ciocalteu, ABTS, and DPPH assays. A comprehensive analysis of different phenolic and other constituents was performed with the use of high-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS). The hot-prepared infusions on average contain considerably more active compounds than the cold-prepared infusions, which resulted in greater antioxidant activity of hot-prepared beverages. While the hot-prepared infusions of pure yerba mate contained a similar amount of bioactive compounds as those with different additives, for cold-prepared beverages, greater antioxidant activity was found for samples containing additives. In both conditions, the lowest antioxidant activity was noted for Ilex guayusa, which contained less rutin, caffeoylquinic acids, dicaffeoylquinic acids, and theobromine, but more caffeine.
Coffee is one of the most popular beverages in the world. Therefore, this study analyzed 49 coffee samples of Arabica and Robusta species of different geographical origins and the treatment of beans including three degrees of roasting with the use of LC-MS/MS. This is the first study to present a comprehensive analysis of Kopi Luwak coffee brew metabolites in comparison to fully washed coffees and the drying post-harvest treatment of Arabica or Robusta coffee brews. Kopi Luwak showed higher levels of caffeine and theophylline in comparison to the analyzed washed and unwashed Arabica coffees, as well as a different proportion of caffeoylquinic isomers. There was no difference between Kopi Luwak and other Arabica coffees in terms of the concentration of vitamin B3, amines, and phenolic acids. This was confirmed in PCA. The steaming and roasting of beans as well as the addition of black beans influence the concentration of 4-CQA and the nicotinic, ferulic, and quinic acids content.