Search

This work proposes a liquid-phase microextraction (LPME) method to extract the highly polar compounds phenol (Ph), o -cresol ( o -Cr), m -cresol ( m -Cr), p -cresol ( p -Cr), and 2,4-dimethylphenol (2,4-DMP) from aqueous matrices. The first extraction step of the LPME method employed a common volumetric flask and n -octanol, and the second extraction step used NaOH as the acceptor phase. The optimized extraction conditions were 900 μL of n -octanol as the extraction solvent, NaOH at 0.60 mol L −1 as the acceptor phase, an extraction time of 5.0 min, HCl at 0.01 mol L −1 and NaCl at 20.0% as the donor phase, and an extraction temperature of 20.0 °C. The analysis of 50.0 mL of aqueous sample, pretreated under the optimized LPME conditions, afforded a limit of detection (LOD) between 0.3 and 3.5 μg L −1 , a limit of quantification (LOQ) between 1.2 and 11.6 μg L −1 , and a linear range from 2.50 to 50.0 μg L −1 for Ph, o -Cr, m -Cr and p -Cr and from 12.5 to 250 μg L −1 for 2,4-DMP. The proposed LPME method was a successful sample preparation strategy, and allowed for precise and accurate quantification of polar phenolic compounds in aqueous matrices such as tap water, river water, groundwater, and seawater, and also in a soil extract. The recovery values ranged from 72.5% to 126.0%, and the relative standard deviation was between 0.3 and 11.5%. [ABSTRACT FROM AUTHOR]

• An HPLC acidic HILIC column shows efficient separation of high-polarity components. • The FBMN-GNPS method allows rapid annotation of amino derivatives in food. • The approach allows rapid identification of compounds in food. • Possible unknown calystegine analogues are present in Solanum species. Calystegines are potent glycosidase inhibitors with therapeutic potential and are constituents of food and feed with potential toxic effects. This study aims to target calystegines and other nitrogenous substances in food plants. Hydroalcoholic extracts from Solanum tuberosum , Ipomoea batatas , S. lycocarpum , and fruit from S. lycopersicum , S. aethiopicum , S. paniculatum , S. crinitum , and S. acanthodes were analyzed by liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) using an acidic HILIC column. The dereplication approach included data processing using MZMine2, FBMN-GNPS, and structure elucidation and interpretation of the organized data. The calystegines A 3 , A 5 , B 2 , and C 1 were identified, and several potential new calystegine analogues : three may correspond to new calystegines of the A-group, one glycosyl derivative of calystegine A 3 , and two glycosyl derivatives of the B-group. These findings help to direct the search for new calystegines. In addition, the dereplication approach enabled the annotation of 22 other nitrogen compounds. [ABSTRACT FROM AUTHOR]

• Low molecular weight PAH was not detected in PAH-loaded MP (MPC) and PAH in combination with virgin MP (PAH+MP) treatments. • The PAH concentration from MPC and PAH+MP was similar. • The virgin MP, PAH, MPC, and PAH+MP was able to cause muscle glycogen depletion. • The activity of v-type H + ATPase and plasma Na+ concentrations were lower only in PAH with MP (MPC) treatment. • The isolated and combined PAH and MP treatments did not affect the mineral water balance (K +, Mg2+, Cl−, and osmolality). Microplastic (MP) pollution poses a significant environmental threat. These MPs can adsorb toxic compounds such as polycyclic aromatic hydrocarbons (PAH), which are highly lipophilic and carcinogenic. To assess the potential effects of virgin MP, PAH, and MP+PAH in association with osmoregulation and energetic substrate, we conducted experiments with the tetra cardinal Astyanax lacustris. The environmentally relevant concentration of MP (10 mg L−1) and 20 % of the LC 50 –96 h of crude oil for A. lacustris (2.28 µg L−1) were used during the 96-h exposure. Fish were exposed to virgin MP, PAH, MPC (MP loaded with PAH), PAH+MP (PAH and MP in association), and the control without (CT) and with handling (CH). After 96 h, blood was collected for osmoregulatory parameters (plasma osmolality; Na+, K +, Cl−, Mg2+; glycose and lactate); gills for osmoregulatory enzyme activities (Na+, K + ATPase, H + ATPase, and carbonic anhydrase); and white muscle samples were used to determine glycogen as an energetic substrate. The low molecular weight PAH was not detected in PAH-loaded MP (MPC) and PAH in combination with MP (PAH+MP). The PAH concentration of the MPC and PAH+MP was similar and low compared to other works. Virgin MP, PAH, MPC, and PAH+MP were able to cause muscle glycogen depletion. The activity of v-type H + ATPase and plasma Na+ concentrations were lower in PAH with MP (MPC). However, the hydromineral balance (K +, Mg2+, Cl−, and osmolality) was not affected by any treatment. In this sense, we can conclude that the MPC caused osmoregulatory disturbances not seen in the MP associated with PAH (MP+PAH). However, this seems unrelated to the PAH leaking from the MPC or the PAH absorption to the virgin MP once the PAH concentrations from the MPC and PAH+MP were similar. [ABSTRACT FROM AUTHOR]

Benzyl butyl phthalate (BBP), which is widely used in industrial production, reaches the aquatic environment, mainly owing to improper disposal of plastic products. In the water, it remains adsorbed to sedimentary particles causing toxic effects in aquatic invertebrates such as Chironomidae, which are important in maintaining ecosystem dynamics and are an important link in the food chain. However, the effects of BBP on Chironomidae are still poorly known. Thus, the toxic effects of BBP on Chironomus sancticaroli at acute (48 h), subchronic (8 d), and chronic (25 d) exposures of concentrations between 0.1 and 2000 μg·L−1 were determined. Genotoxicity effects, changes in the oxidative stress pathway, and development and emergence of organisms were evaluated. Biochemical markers showed a reduction in cholinesterase (ChE) activity, indicating a neurotoxic effect on acute exposure (1–1000 μg·L−1). The antioxidant pathway, glutathione S-transferase (GST) activity showed reduction on acute (0.1; 1–2000 μg·L−1) and subchronic (1–2000 μg·L−1) exposures and reduction in superoxide dismutase (SOD) activity at all evaluated concentrations, suggesting oxidative stress. In contrast, lipid peroxidation was not observed. DNA damage occurred on acute (10 μg·L−1) and subchronic (10–2000 μg·L−1) exposures, indicating genotoxic effects. At concentrations above 10 μg·L−1, no emergence of adults occurred, while lower concentrations (0.1 and 1 μg·L−1) showed a reduction in the number of adults, mainly males. The observed effects indicate that BBP is genotoxic and causes biochemical alterations presenting high toxicity at the population level. Unlabelled Image • DNA damage on acute and subchronic exposure indicates genotoxicity of BBP. • BBP causes neurotoxic effect on acute exposure. • SOD activity increase with subchronic exposure suggests presence of oxidative stress. • Larvae show delay in development after subchronic exposure. • High BBP concentrations inhibit emergence of adult C. sancticaroli. [ABSTRACT FROM AUTHOR]

Contamination of aquatic environments by petroleum and its products (e.g. gasoline) is a hazard for aquatic organisms as a result of the potential toxicity of monocyclic aromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAH). Our goal was to evaluate the acute effects of the water-soluble fraction of gasoline (WSF G) on nitrogen excretion, osmoregulation, and metabolism of goldfish Carassius auratus. We first chemically characterized the WSF G and then tested its effects on these physiological aspects of C. auratus , in several different exposure scenarios (0, 0.25, 5, 10 and 25% of WSF G). The WSF G contained high concentrations BTEX (toluene 70% and benzene 17%) relative to PAH (<1%), and low levels of several metals (Al, Fe, Zn, Sr). Routine O 2 uptake rate (M O 2) of goldfish was inhibited by exposure to 5% WSF G , and during post-exposure recovery, M O 2 increased in a dose-dependent fashion. Ammonia excretion was not affected by exposure to WSF G , but urea-N excretion increased progressively with the WSF G concentration. The same pattern of dose/response was observed for net Mg2+ loss rates and steadily increasing plasma lactate concentrations. Loss rates of Na+, Ca2+, K+ and Cl−, and plasma concentrations of Mg2+ and urea-N were not significantly altered. We propose that acute exposure to WSF G inhibits aerobic metabolism and activates anaerobic metabolism, breaking down ATP such that bound Mg2+ is liberated and the purine ring component is metabolized to urea-N, both of which are subsequently excreted. Unlabelled Image • Exposure to WSF G inhibited aerobic metabolism and activated anaerobic metabolism in goldfish. • Urea-N and Mg2+ excretion increased, likely reflecting ATP breakdown • Ammonia excretion was not affected. • Routine O 2 uptake rate (M O 2) of goldfish was inhibited. • M O 2 increased during post-exposure recovery. [ABSTRACT FROM AUTHOR]