Analysis Of Water Samples Research Articles

A nitrogen-rich functionalized magnetic COF-based MSPE method coupled with HPLC-MS/MS for sulfonamide analysis in water samples

Highly selective detection of trace Lead(II) ions based on MoS2 QDs/TiO2 NRs photoelectrochemical sensing.

Photoinduced chemiluminescence method for the determination of acetamiprid and pendimethalin with flow injection analysis in fruit and water samples

Conventional solution-based fluorescent probes are often constrained in practical application by insufficient portability and a reliance on complex instrumentation. To overcome these limitations, this study developed a portable, hydrogel-based ratiometric sensor integrated with a smartphone readout platform for the visual, on-site detection of Cu2⁺. The sensor was synthesized by co-embedding blue-emissive MoS₂ quantum dots (QDs) and red-emissive CdTe QDs@SiO₂ nanoparticles within a gelatin/glycerol hydrogel matrix. Upon exposure to Cu2⁺, the sensor exhibits a distinct colorimetric transition from blue to red, which is quantitatively captured and detected using a smartphone color analysis application. This method achieves a detection limit as low as 33.2nM and demonstrates excellent long-term stability (32days). The sensor's practicality was validated through the analysis of environmental water samples, yielding high accuracy and reproducibility. This work establishes a novel, portable, and instrument-free ratiometric hydrogel sensor strategy, leveraging smartphone technology for effective on-site Cu2⁺ monitoring in water resources.

CoNiFe-LDH nanoflowers combined with bismuth-based layered perovskite oxide (Bi₂MoO₆) for vortex-assisted micro-solid phase extraction of lead from food and water samples.

In recent decades, the demand for the consumption of bottled drinking water has been increasing. Drinking water is an irreplaceable food product in human nutrition, therefore, in addition to processing, permanent quality control is also required. The object of the study in this paper was the analysis of several quality parameters in two types of bottled water in glass and plastic (PET). Sampling was carried out in the market of the city of Tetovo. The samples were analyzed for qualitative parameters: sensory (color, aroma, taste), physical and chemical (pH, turbidity and electrical conductivity). The results obtained in the analyzed samples showed that they are identical to those declared on the packaging label, although the water was from the same source, there were differences in the results for the analyzed parameters, but they were minimal. Sensory parameters as in the sample in plastic and glass packaging, the color was characteristic for drinking water without foreign color, the aroma without odor and without foreign taste, the pH level was almost identical between the analyzed samples with very small deviations. Based on the electrical conductivity and turbidity in the analyzed water samples, the water packaged in glass had lower values and better quality results.

Between April and May 2025, an outbreak of travel-associated Legionnaires’ disease (TALD) occurred, involving six cases at a hotel in Crete, Greece. Including two cases reported in 2023 and two additional cases from 2016 to 2017, ten cases were associated with this accommodation site. All TALD cases were reported by the European Legionnaires’ Disease Surveillance Network (ELDSNet). In compliance with the European Centre for Disease Prevention and Control (ECDC) surveillance and investigation protocols for hotels associated with the patient’s stay, local public health authorities conducted on-site inspections at the hotel by collecting water samples and performing risk assessments, while simultaneously recording the required epidemiological, environmental, and physicochemical data. A total of 181 statistically analyzed water samples showed positive rates for L. pneumophila of 12.71% (95% CI: 7.86–17.56) for (≥50 CFU/L) and 6.08% (95% CI: 2.60–9.56) for (≥1000 CFU/L). Risk assessments identified 18 stagnation points, systemic maintenance deficiencies, and high cumulative structural (30/52) and water (36/71) system risk scores. Low microbiological positivity of water samples does not necessarily equate to low risk, thus necessitating continuous risk assessment, implementation of Water Safety Plans (WSPs), and integrated monitoring by accommodation facilities to prevent LD cases.

A fundamental technical challenge in detecting pathogenic bacteria in aquatic reservoirs is the inability to accurately estimate biofilm-associated cells in water. Considering the role of biofilms in environmental persistence and waterborne transmission of bacterial pathogens, there is an increasing interest in substances that can effectively degrade bacterial biofilms. The biofilm-dispersing Vibrio cholerae phage JSF7 was analyzed by whole genome sequencing and found to carry a gene predicted to encode an enzyme for degrading complex polysaccharides. The gene was cloned in Escherichia coli DH5α, and crude extract from the recombinant E. coli enhanced the dispersion of diverse bacterial biofilms, including those of E. coli, Shigella dysenteriae, Pseudomonas aeruginosa, and V. cholerae. The crude extract was fully active at a temperature of 37°C and pH of 7.0 but was inactivated by proteinase-K treatment. Analysis of environmental water samples for the presence of V. cholerae O1 by enrichment culture detected significantly more V. cholerae O1-positive samples when the enrichment medium was supplemented with the extract, as compared with typical enrichment without the extract. These results suggest that a crude preparation of the phage-encoded biofilm-degrading factor expressed in E. coli has potential application in degrading bacterial biofilms and enhancing bacteriological analysis of water.IMPORTANCEIn their aquatic reservoirs, bacteria often exist as biofilms and are difficult to accurately detect by culturing water samples. Such biofilms have been implicated in waterborne transmission of pathogenic bacteria. We identified a bacteriophage that can disintegrate biofilms and disperse biofilm-associated bacteria. The putative phage gene responsible for this activity was cloned in an E. coli strain, and the crude cellular extract of the recombinant E. coli was found to promote dispersion of a variety of bacterial biofilms. Supplementation of bacterial growth medium with the crude extract also enhanced detection of V. cholerae O1, the causative agent of cholera in environmental water samples. The ability of a phage-derived biofilm-degrading factor to disperse diverse bacterial biofilms provides a novel approach for enhancing detection of waterborne bacterial pathogens in water beyond traditional enrichment methods.

Multifunctional molecular imprinting-enhanced transistor and electrochemical dual-mode sensor for ultra-wide range detection of halogenated phenols.

Phuoc Nhon thermal water at Hoa Khuong commune, Hoa Vang district, Da Nang City (prior to the provincial administrative merger on 1 st July 2025), Vietnam. The thermal mineral water is distributed within a fractured rock aquifer hosted in the intrusive rocks of Dai Loc Complex. Methods used in this study consist of basic field survey of hydrogeology, self - flowing water discharge tests, pumping tests, and thermal mineral water sample analysis. The thermal mineral water is classified as fluoridated, low mineralised thermal mineral water. Its exploration reserve is estimated at 425 m 3 /d with good quality, satisfying all national criterials for the use of domestic supply, bathing, and medical treatments. This is one of the valuable fluoridated natural mineral water sources, which should be properly managed, exploited, protected, and utilized in a scientific, rational, and efficient manner.

Abstract The analysis of water samples taken from 14 points along the Kura River, the principal waterway in the South Caucasus, including Azerbaijan, allowed for the determination of fluctuations in the amount of mineralization, especially in the concentration of the major ions during the monitoring conducted between 2020 and 2022 by the Central Laboratory of “Azersu” OJSC (now Azerbaijan State Water Resources Agency), starting from the Georgian border to the river mouth. The findings discovered a consistent increase in mineralization towards the river mouth. Sample points in Kura River are selected to reflect the water quality before and after major interference into the river-reservoir, tributary sewage, etc. Seasonal variations and anthropogenic influences, particularly agricultural runoff and tributaries flow, contribute to significant changes in ion concentrations. The results provide a robust background for future research and policymaking to enhance the region’s water quality monitoring and management strategies. Significantly, the mineralization value experiences a 2.5-fold increase shortly after merging with the Aras River, with the concentration at the Neftchala station surpassing 3000 mg/l. This represents an 8.8-fold increase compared to the value observed at the I Shikhli station. Alongside natural factors, anthropogenic activities contribute to the elevated concentration of major ions. The sulfate ion concentration, for instance, demonstrates a 1.8 to 2.1-fold increase, while the chloride ion concentration escalates by 3 to 10 times. Additionally, the combined sum of sodium and potassium experiences a 2 to 2.5-fold increase. The concentration of magnesium ions remains constant throughout the river, constituting approximately 4 to 5% of the major ions. Conversely, there is a notable decrease in the concentration of bicarbonate ions by 2.3 to 8.5 times and a decrease in the concentration of calcium ions by 1.3 to 2 times. Consequently, the chemical composition of the river water transitions from calcium-bicarbonate waters to sodium-sulfate waters downstream of the Kura River, since in the chemical composition of the river water from Zardab to the estuary, sulfate ion prevails over bicarbonate, and the sum of sodium–potassium surpasses calcium.

A method based on solid-phase extraction (SPE) has been developed for the preconcentration of three kinds of ethyleneamines (EAs) [ethylenediamine (EDA), diethylenetriamine (DETA), and triethylenetetramine (TETA)] in river water for their high-performance liquid chromatographic (HPLC) determination by using on-line complexation with Cu(II) ion and ultraviolet (UV) detection. EAs, which are protonated in acidic and neutral conditions, could be concentrated by using cation-exchange SPE. However, inorganic cations and humic substances, often present in river water, interfered with this preconcentration. Inorganic cations, such as Ca and Mg ions, compete with EAs in cation-exchange processes. This interference could be reduced by masking them with ethylenediaminetetraacetic acid. Humic substances, such as humic acid and fluvic acid, seem to be due to the electrostatic interaction of EAs with them in the sample solution. This interference was reduced by passing the sample solution through an anion-exchange cartridge before the cation-exchange SPE. The interacted EAs remained in the anion-exchange cartridge; they could be eluted by washing out the anion-exchange cartridge with diluted HCl. In this washing process, although fulvic acid was eluted at the same time, it could be removed by passing the eluate through a reversed-phase cartridge connected in a series. After removing these interferences, EAs could be extraced with the cation-exchange SPE and quantitatively eluted by passing Cu(II) solution through the cartridge. The proposed method of including the HPLC-UV combined with the SPE was available for the determination of EAs in river water at concentrations as low as 0.015µM for EDA and DETA and 0.05µM for TETA. The high recoveries (83%-103%) and repeatabilities (RSD 1.2%-4.3%) were obtained for EAs from two river water samples spiked with two different concentrations of EAs. The proposed method was applied to analyses of river water samples taken from four rivers in Toyama Prefecture, Japan.

ABSTRACTThe environmental occurrence of psychiatric drugs is a growing concern due to their widespread use and persistence in aquatic systems. In this study, haloperidol and aripiprazole, two commonly prescribed antipsychotic agents, were selected as model compounds to investigate their photocatalytic modification and assess the formation of transformation products (TPs). A high‐performance liquid chromatography–high‐resolution mass spectrometry (HPLC–HRMS) method was developed for the identification and structural elucidation of TPs generated via TiO2‐mediated heterogeneous photocatalysis in ultrapure water. Reverse‐phase chromatographic separation was achieved using an octadecyl silica column as the stationary phase, with formic acid and acetonitrile as the mobile phase. The total run time of 37 min provided adequate resolution for the separation of the main TPs isomers. TPs annotation was carried out using orbitrap technology, operated at a resolving power of 60 000 for all experiments. Including isomers, a total of 32 haloperidol TPs and 13 aripiprazole TPs were identified, with proposed fragmentation pathways established through targeted MSn experiments. The method was then applied to the analysis of real river surface water samples collected from the Po and Sangone Rivers in Northern Italy over a 3‐month period. Following solid‐phase extraction (SPE), both parent compounds and TPs were recognized and semi‐quantified by retention time, exact mass, and MS2 spectral data. Haloperidol and aripiprazole were detected at maximum concentrations of 27 and 67 ng L−1, respectively. To assess the potential biological impact, in vitro cytotoxicity tests were conducted on normal (BEAS‐2B) and oncogenic (BEAS G12C) human bronchioalveolar epithelial cell lines. Although the parent drugs exhibited negligible toxicity at the tested concentrations, haloperidol TPs induced marked cytotoxic effects in both cell models. These results highlight the necessity of including TPs in environmental monitoring and toxicological assessments.

Detection of ninhydrin-glyphosate in groundwater via the colour chart-assisted digital camera method.

Microplastic in tropical island estuaries in China: Source identification and management framework development.

High-resolution sampling reveals a considerable year-round risk potential for aquatic organisms in an urban estuary of the Baltic Sea due to anthropogenic pollution mixture.

The Ural River is the main source of water supply for Atyrau Region, providing drinking water not only to the city of Atyrau but also to settlements in the Inder, Makhambet, and Makat districts. Therefore, its quality and hydrological regime are of strategic importance. In achieving SDG targets 6.1 and 6.2, related to access to safe drinking water and sanitation in Kazakhstan’s rural areas, the hydrochemical regime of the Ural River and the influence of the hydrochemical water regime of the North-Eastern Caspian Sea play a crucial role. This article presents hydro-physical and hydrochemical indicators obtained during field geo-ecological studies. Based on the chemical analysis of water samples from key sites, the current state and hydrochemical regime of surface waters are described.

Isolation of Antibiotic-Resistant Bacteria from a Water Sample for Molecular Analysis

Herein, cellulose acetate membrane modified with polyethylene terephthalate derived MIL-101(Fe) (PET-MIL-101(Fe)) was used as an extraction phase for the direct immersion-thin film microextraction method (DI-TFME) of neonicotinoid insecticides in water samples. The quantitative analysis of clothianidin, imidacloprid, thiacloprid and thiamethoxam was carried out using high-pressure liquid chromatography (HPLC-DAD). The morphological and structural characteristics of the materials were studied using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and energy dispersive X-ray spectrometry (EDX). Under optimum conditions, acceptable analytical performance for the developed DI-TFME/HPLC-DAD method was attained. The linearity of the method ranged from 0.04 to 500 µg/L with R2 ranging from 0.9981 to 0.9989. The detection limits, quantification limits and relative standard deviation (%RSD) of the DI-TFME/HPLC-DAD method were in the range of 0.013–0.016 µg/L, 0.043–0.053 µg/L and 1.2–3.9%, respectively. The method was applied in the analysis of real water samples, and the spiking recoveries of the target analytes were 95.6–102%, 91.2–98.6% and 79.2‒98.7% for river water, effluent and influent samples, respectively, with %RSDs ranging from 1.8 to 4.8%. These findings demonstrated that the developed DI-TFME/HPLC-DAD method had high precision, accuracy, sensitivity and enrichment factor (73–88). The DI-TFME/HPLC-DAD method proved sustainable for the simultaneous quantification of trace neonicotinoid insecticides in real samples.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-18447-3.

Switchable deep eutectic solvents have attracted increasing attention from researchers due to their unique characteristics of responding to the external environment. In this experiment, a series of temperature-responsive deep eutectic solvents (TRDESs) were prepared with temperature as the response condition and combined with homogeneous liquid-liquid microextraction (HLLME) for the detection of six triazole pesticides in environmental water. TRDES-HLLME achieved excellent linearity for pesticides (R2 > 0.9968). The enrichment factors (EFs) ranged from 26 to 34. Additionally, the limits of detection (LODs) and the limits of quantification (LOQs) varied between 1.24 and 2.76 μg L-1 and 4.12 to 9.19 μg L-1, respectively. The intra-day and inter-day relative standard deviations (RSDs) of all target analytes were below 5.5% and 7.4%, respectively. Spiked recoveries ranged from 74.1% to 110.0%. TRDES-HLLME's superior greenness and broad applicability were validated through the implementation of three distinct green assessment tools.