RESUMEN
Exploring disinfection byproducts (DBPs) with adverse health effects in drinking water is a constant challenge. Halobenzamides (HBZAMs) are suspected to be a new group of nitrogenous DBPs but have not been reported in drinking water to date. In this study, by coupling SPE and UPLCâMS/MS, a sensitive method was established to detect eight HBZAMs in drinking water with recoveries and limits of detection of 80-103% and 0.01-0.04 ng/L, respectively. Subsequently, distinct fragments of HBZAMs were extended to the development of a pseudotargeted method for the analysis of the fourteen HBZAMs that were speculated and lack chemical standards. Using the developed method, eight HBZAMs were quantified in ten drinking water samples with concentrations ranging from 2.4 to 7.2 ng/L and a detection frequency of 100%, among which five HBZAMs were stable with half-lives over 72 h under real chlorine levels. Twelve HBZAMs without standards were identified in three to ten drinking water samples with comparable levels. The cytotoxicity of eight quantified HBZAMs in CHO-K1 cells varied with disparity, in which the cytotoxicity of 3,5-DBBZAM was over 10-fold higher than that of aliphatic dichloroacetamide. Considering their diversity, toxicity and stability, the occurrence of HBZAMs in drinking water deserves attention.
Asunto(s)
Desinfectantes , Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Cricetinae , Animales , Desinfección/métodos , Agua Potable/análisis , Desinfectantes/toxicidad , Desinfectantes/análisis , Cromatografía Liquida , Nitrógeno/análisis , Purificación del Agua/métodos , Espectrometría de Masas en Tándem , Halogenación , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , CricetulusRESUMEN
Synthetic cannabinoids, one of the most widely abused new psychoactive substances (NPS), are now placed under national control generally in China. Due to continuous modification of synthetic cannabinoid structure, an ongoing dilemma in the forensic laboratory is that newly emerging substances cannot be detected by established methods. Thus, the screening methods for simultaneous detection of known or unknown substances have become research hotspots. In this study, the ultra high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-QqQ-MS) with precursor ion scan (PIS) as acquisition mode was used for prescreening purposes of all possible synthetic cannabinoids-related substances. In detail, four common characteristic fragments, m/z of 144.0, 145.0, 135.1, and 109.0 corresponding to acylium-indole, acylium-indazole, adamantyl, and fluorobenzyl cation respectively, were selected for PIS mode, and their collision energies were optimized by 97 available synthetic cannabinoids standards with relevant structures. Those suspicious signals observed in the screening experiment were confirmed by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) via high-resolution MS and MS2 data obtained by full scan (TOF MS) and product ion scan mode. After methodological validation, the integrated strategy established above was applied to the screening and identification of the seized e-liquids, herbal blends and hair samples, confirming the presence of multiple synthetic cannabinoids in these samples. In particular, a novel synthetic cannabinoid was identified as 4 F-ABUTINACA, for which no relevant high-resolution mass spectrometry (HRMS) data has been retrieved until now, making this study the first to report the cleavage pattern of this compound in electrospray ionization (ESI) mass spectrometry. In addition, four other suspected by-products of the synthetic cannabinoids were found in the herbal blends and e-liquids, and their possible structures were also deduced via the information from high-resolution mass spectra.
Asunto(s)
Cannabinoides , Espectrometría de Masa por Ionización de Electrospray , Cromatografía Líquida de Alta Presión , Cannabinoides/análisis , Cabello/química , ChinaRESUMEN
Halobenzoquinones (HBQs) as disinfection byproducts (DBPs) in drinking water is prioritized for research due to their prevalent occurrence and high toxicity. However, only fifteen HBQs can be identified among a high diversity using targeted LC-MS/MS analysis in previous studies due to the lack of chemical standards. In this study, we developed a pseudo-targeted LC-MS/MS method for detecting and quantifying diverse HBQs. Distinct fragment characteristics of HBQs was observed according to the halogen substituent effects, and extended to the development of a multiple-reaction-monitoring (MRM) method for the quantification of the 46 HBQs that were observed in simulated drinking water using non-targeted analysis. The fragmentation mechanism was supported by the changes of Gibbs free energy (ΔG), and a linear relationship between the ΔG and the ionization efficiency of analytes was developed accordingly for quantification of these 46 HBQs, 30 of which were lack of chemical standards. It is noted that 29 of the 30 newly-identified HBQs were halo-methyl-benzoquinones (HMBQs), which were predicted to be carcinogens related with drinking-water bladder cancer risk and be more toxic than non-methyl HBQs. Using the new method, twelve HMBQs were detected in actual drinking water samples with concentrations up to 100.4 ng/L, 3 times higher than that reported previously. The cytotoxicity in CHO cells of HMBQs was over 1-fold higher than that of non-methyl-HBQs. Therefore, HMBQs are an essential, highly toxic group of HBQs in drinking water, which deserve particular monitoring and control.