Bromhexine and ambroxol are among the mucolytic drugs most widely used to treat acute and chronic respiratory diseases. Entering the municipal wastewater and undergoing transformations during disinfection with active chlorine, these compounds can produce nitrogen- and bromine-containing disinfection by-products (DBPs) that are dangerous for aquatic ecosystems. In the present study, primary and deep degradation products of ambroxol and bromhexine obtained in model aquatic chlorination experiments were studied via the combination of high-performance liquid and gas chromatography with high-resolution mass spectrometry. It was shown that at the initial stages, the reactions of cyclization, hydroxylation, chlorination, electrophilic ipso-substitution of bromine atoms with chlorine, and oxidative N-dealkylation occur. Along with known metabolites, a number of novel primary DBPs were tentatively identified based on their elemental compositions and tandem mass spectra. Deep degradation of bromhexine and ambroxol gives twenty-four identified volatile and semi-volatile compounds of six classes, among which trihalomethanes account for more than 50%. The specific class of bromhexine- and ambroxol-related DBPs are bromine-containing haloanilines. Seven of them, including methoxy derivatives, were first discovered in the present study. One more novel class of DBPs associated with bromhexine and ambroxol is represented by halogenated indazoles formed through dealkylation of the primary transformation products containing pyrazoline or tetrahydropyrimidine cycle in their structure.

Peat was studied in order to assess the concentrations of heavy metals in it depending on the depth of occurrence. Genetically homogeneous peat layers with

Detecting and quantifying disinfection by-products (DBPs), especially brominated species (Br-DBPs), is analytically challenging, often necessitating multiple techniques and specific standards for each target. This complexity hinders comprehensive assessment. To overcome these limitations, we present a powerful, integrated approach combining liquid chromatography with inductively coupled plasma mass spectrometry (LC-ICP-MS) and high-resolution mass spectrometry (LC-HRMS). This method enables rapid, non-targeted group screening of Br-DBPs: LC-ICP-MS selectively identifies bromine-containing compounds, while LC-HRMS provides tentative structural identification. Crucially, this synergistic combination allows for the quantification of any Br-DBP without requiring individual reference standards. This study successfully demonstrates the application of this combined LC-ICP-MS and LC-HRMS strategy for the non-targeted detection, identification, and subsequent quantification of Br-DBPs in real drinking water samples, offering a significant advancement for DBP monitoring and risk assessment.

Lignin is one of the most abundant biopolymers. Information about the functional composition and structure of various lignins may be useful in the study of biosynthesis processes in plants. The subject of the article is the determination of 31P-NMR spectroscopy possibilities to identify lignins obtained from various plant forms. To obtain spectra on 31P nuclei, a modification of the studied samples was applied by phosphitylating their OH-groups with a special reagent. We obtained qualitative and quantitative analysis of samples of softwood and hardwood lignins and herbaceous plants. According to the NMR spectra we noted the differences in composition and structure of the studied lignins. We confirmed that the structure of lignins of softwood and hardwood wood mainly contain guaiacilpropane and syringylpropane structural units, respectively. We found that lignins of herbaceous plants contain all types of OH-groups characteristic for lignins, including p-hydroxyphenyl groups. It was observed that samples of herbaceous plants lignins contain fragments of flavonoid structures in most cases. The 31P-NMR spectrum of quercetin, as the flavonoids representative, was registered and also modeled using the ACDLabs software package to confirm the presence of flavone structures in the macromolecules of the herbaceous lignins.