Water Samples Research Articles

Dissolved trace elements and nutrients in the North Sea—a current baseline

Primary production is an important driver of marine carbon storage. Besides the major nutrient elements nitrogen, phosphorus, and silicon, primary production also depends on the availability of nutrient-type metals (e.g., Cu, Fe, Mo) and the absence of toxicologically relevant metals (e.g., Ni, Pb). Especially in coastal oceans, carbon storage and export to the open ocean is highly variable and influenced by anthropogenic eutrophication and pollution. To model future changes in coastal carbon storage processes, a solid baseline of nutrient and metal concentrations is crucial. The North Sea is an important shelf sea, influenced by riverine, atmospheric, Baltic Sea, and North Atlantic inputs. We measured the concentrations of dissolved nutrients (NH4+, NO3−, PO43−, and SiO44−) and 26 metals in 337 water samples from various depths within the entire North Sea and Skagerrak. A principal component analysis enabled us to categorize the analytes into three groups according to their predominant behavior: tracers for seawater (e.g., Mo, U, V), recycling (e.g., NO3−, PO43−, SiO44−), and riverine or anthropogenic input (e.g., Ni, Cu, Gd). The results further indicate an increasing P-limitation and increasing anthropogenic gadolinium input into the German Bight.

Prevalence of T-2 Toxin in the Food and Beverages of Residents Living in a Kashin–Beck-Disease Area of Qamdo, Tibet

It has been strongly suggested that selenium deficiency and T-2 toxin contamination have a strong relationship with the occurrence and development of Kashin–Beck disease (KBD). In order to provide information for understanding the high prevalence of KBD in Tibet, this study collected the responses to a cubital venous blood and dietary questionnaire of 125 subjects including 75 KBD patients and 50 healthy controls in a KBD-prevalent county (Luolong County) in Tibet, China. A total of 10 household local families were randomly selected in this area, and local diet samples of brick tea, Zanba powder, milk residue, and hulless Barley were collected from these residents. Selenium content in blood was detected by inductively coupled plasma mass spectrometry (ICP-MS). The T-2 toxin contamination level in food sample was assayed using an ELISA kit. The selenium levels of patients and controls were 42.0 ± 19.8 and 56.06 ± 22.4 μg/L, respectively. The serum selenium level in controls was higher than that in patients, but there was no significant difference, and the serum selenium level both in patients and controls in Tibet was lower than the normal range. The results of the dietary survey showed that the number of respondents who consumed butter tea was large; 46.67% of patients indicated that they drank buttered tea every day, which was significantly higher than in controls. The contents of T-2 toxin in Zanba powder, milk residue, hulless barley and drinking water samples were below the detection limit (0.05 μg/kg); this result was labeled Tr. Unexpectedly, the contents of T-2 toxin in brick tea were higher, with average levels of 424 ± 56 μg/kg in Detong village and 396 ± 24 μg/kg in Langcuo village. For the first time, we report the presence of an extremely high concentration of T-2 toxin in brick tea of Tibet.

Microbial community response to hydrocarbon exposure in iron oxide mats: an environmental study

Hydrocarbon pollution is a widespread issue in both groundwater and surface-water systems; however, research on remediation at the interface of these two systems is limited. This interface is the oxic–anoxic boundary, where hydrocarbon pollutant from contaminated groundwaters flows into surface waters and iron mats are formed by microaerophilic iron-oxidizing bacteria. Iron mats are highly chemically adsorptive and host a diverse community of microbes. To elucidate the effect of hydrocarbon exposure on iron mat geochemistry and microbial community structure and function, we sampled iron mats both upstream and downstream from a leaking underground storage tank. Hydrocarbon-exposed iron mats had significantly higher concentrations of oxidized iron and significantly lower dissolved organic carbon and total dissolved phosphate than unexposed iron mats. A strong negative correlation between dissolved phosphate and benzene was observed in the hydrocarbon-exposed iron mats and water samples. There were positive correlations between iron and other hydrocarbons with benzene in the hydrocarbon-exposed iron mats, which was unique from water samples. The hydrocarbon-exposed iron mats represented two types, flocculent and seep, which had significantly different concentrations of iron, hydrocarbons, and phosphate, indicating that iron mat is also an important context in studies of freshwater mats. Using constrained ordination, we found the best predictors for community structure to be dissolved oxygen, pH, and benzene. Alpha diversity and evenness were significantly lower in hydrocarbon-exposed iron mats than unexposed mats. Using 16S rDNA amplicon sequences, we found evidence of three putative nitrate-reducing iron-oxidizing taxa in microaerophile-dominated iron mats (Azospira, Paracoccus, and Thermomonas). 16S rDNA amplicons also indicated the presence of taxa that are associated with hydrocarbon degradation. Benzene remediation-associated genes were found using metagenomic analysis both in exposed and unexposed iron mats. Furthermore, the results indicated that season (summer vs. spring) exacerbates the negative effect of hydrocarbon exposure on community diversity and evenness and led to the increased abundance of numerous OTUs. This study represents the first of its kind to attempt to understand how contaminant exposure, specifically hydrocarbons, influences the geochemistry and microbial community of freshwater iron mats and further develops our understanding of hydrocarbon remediation at the land–water interface.

Simultaneous determination of eight neonicotinoid insecticides and five metabolites in water samples by liquid chromatography‐tandem mass spectrometry unveils an overlooked risk

AbstractNeonicotinoids (NEOs), highly selective toward insect nicotinic acetylcholine receptors, are extensively used due to their effectiveness against pests and relative non‐toxicity to vertebrates. However, their prolonged persistence in soil and water has led to frequent detection in food and environmental samples, posing significant environmental and health concerns. Recent research indicates these pesticides infiltrate aquatic ecosystems, threatening aquatic life and human health. Here, we improved the ultra‐performance liquid chromatography‐mass spectrometry method for detecting NEOs in water samples, increasing its sensitivity to fulfill forthcoming detection needs. This approach enables the simultaneous quantification of eight NEOs and five NEO metabolites in diverse water sources, including tap, surface, groundwater, sewage, and seawater. Our method achieves remarkably low detection limits for direct injection (0.78–1.7 ng/L) and solid‐phase extraction methods (0.13–0.25 ng/L). Critically, our findings reveal that boiling domestic drinking water doesn't degrade NEOs; instead, it increases their concentration due to water evaporation. A 6‐min boiling period can amplify pesticide concentration by 4–5 times, presenting a significant hazard in culinary practices of specific regions where prolonged cooking could lead to alarmingly high levels of these insecticides. This research underscores the importance of monitoring and mitigating NEO contamination in water sources to safeguard environmental and public health.

Are the biodistribution and metabolic effects of copper nanoparticles dependent on differences in the physiological functions of dietary fibre?

Abstract The aim of the study was to determine the effect of the recommended (6.5 mg/kg) or enhanced (13 mg/kg) level of CuNPs in the diet in combination with different types of dietary fibre – cellulose (control), inulin, pectin, or psyllium on the Cu biodistribution and level of selected minerals parameters in the blood of rats. Rats were randomly divided into 10 groups. The first two groups were fed control diets containing cellulose and a mineral mixture with standard or enhanced content of CuCO3. Experimental groups were fed a diet supplemented with CuNPs (6.5 or 13 mg/kg) and combined with different types of fibre (cellulose, pectin, inulin, or psyllium). After the feeding period blood, liver, brain, and thigh samples were collected. In the samples of water, diet, urine, feces, liver, brain, and thigh the Cu content was determined to assess Cu biodistribution in the body. Additionally, the concentrations of minerals (Cu, P, Ca, Mg, Fe, and Zn) in the blood plasma samples were measured. The replacement of CuCO3 with CuNPs in the diet beneficially influenced the biodistribution of Cu in the body by reducing its excretion, improving its digestibility, and utilization, reducing its accumulation in the brain and muscle, and increasing levels of Ca, P, Mg, Zn and Fe in the blood. Increasing the level of CuNPs in the diet increased total Cu intake. The addition of pectin, inulin and psyllium to the diet with a high content of CuNPs significantly increased the excretion of Cu, with no negative effect on its digestibility, and utilization, and prevented its excessive accumulation in the brain and muscle of rats, especially in the case of inulin. The results suggest that the addition of dietary fibre to the diet of rats ensures homeostasis of this element in the case of excessive intake of CuNPs by modifying the bioavailability of Cu.

Groundwater Quality Status of the Parambikulam Aliyar Palar Basin, Tamil Nadu, India Using RS and GIS Techniques

The dependency of ground water is rising day by day. The ground water gets recharged mainly through rainfall. Thirty five water samples were collected from Parambikulam Aliyar Palar basin from open wells, bore wells and dug cum bore wells and analysed for chemical properties such as pH, Electrical Conductivity, cations and anions for two years duration (2020 and 2021) at three months interval (summer, winter, southwest monsoon, northeast monsoon) and analysed for the quality parameters. T Electrical conductivity values were ranged from 0.3 to 5.19 dsm-1, 0.29 to 6.80 dsm-1 0.3 to 6.84 dsm-1 and 0.64 to 4.17 dsm-1 during south west, north east, winter and summer seasons of 2020, respectively. The salt content was slightly increased during winter and summers seasons as compared to south west and north east. he samples were classified under USSL classification. Most of the samples come under medium salinity class (C2) (48.57%) followed by low salinity class (C1), high salinity class (C4) and very high salinity class (C3) with 28.57, 14.29 and 8.57 per cent respectively in all the seasons. Majority of the samples exhibit there is no permeability hazard. Salinity persists in the basin and possibility of salt accumulation in irrigation pipes observed from LSI values. Using remote sensing and GIS technique, the mapping was done for the groundwater quality of PAP basin. The variations in the ground water quality of the basin are directly positively correlated with rainfall pattern and geology of the basin. For effective utilization of saline water in the basin, management strategies were formulated and field experiments were conducted in the farmer’s holdings in the sampling area of the basin.

Aluminum dynamics in nitrogen‐saturated Andisols in Tokyo

AbstractThe debate over whether forests around the Tokyo metropolitan area are nitrogen (N) saturation persists, as atmospheric N deposition in throughfall has decreased. This decrease is evidenced by a notable decline in samples collected in the 1990s (especially 1991–1992 and 1995). This decline can be attributed to a reduction in nitrogen oxide (NOx) emissions from automobiles. The acidity derived from N deposition can increase aluminum (Al) mobility. We conducted a monitoring study from September 2010 to December 2021 to elucidate the effects of decreased N deposition on Al concentrations and flux in a forested Andisol. Throughfall and soil‐percolated water samples were collected under stands of Japanese cedar and Japanese cypress in Hachioji, Tokyo (Field Museum Tamakyuryo). Major inorganic ions were determined by ion chromatography. Total Al concentrations were determined using atomic absorption spectrometry after concentration under acidic conditions. Aluminum and nitrate () concentrations were significantly correlated in the both Japanese cedar and Japanese cypress stands. In the case of the Japanese cedar stand, Al concentrations tended to decrease over time from November 2010 to May 2015. Based on stepwise multiple regression analysis, acid load associated with N transformation ([H+]load) was chosen as the sole factor affecting Al mobilization in the Japanese cedar stand. Decreased N deposition affects Al dynamics via a decrease in [H+]load.

Exploring the Prevalence of Microorganisms in Selected Water Sources in Benue South of Nigeria using Selected Environmental Factors and Microbial Counts

In this study, we assessed the water and microbial qualities of major water sources in nine sites within three Local Government Areas (LGAs-Otukpo, Ohimini and Apa LGAs) in Benue South between January and March, 2023. Water samples were collected monthly for the analyses of selected physico-chemical variables and microbial constituents in the studied sites following standard procedures. The results of the physico-chemical variables showed that most of the variables were proportionately higher than the maximum standards by appropriate regulatory bodies. For instance, electrical conductivity (EC) was highest in S2-Upu borehole, Otukpo LGA (1,181+285 µS/cm) and lowest in S4-Okpokwu River, Ohimini LGA (19.35+6.35 µS/cm). The concentration of dissolved oxygen (DO) in all the sites showed less aerated water except for S2 (5.37+0.34 mg/l) and 5S-Awulema borehole, Ohimini LGA (5.06+0.14 mg/l). On the microbial quality, the results of the total coliform counts from the nine sampling sites (water sources) showed that the highest coliform count (>1,600 MPN/100mL) was recorded in S1 in January 2023 while the lowest coliform count (12 MPN/100mL) was recorded in S2. The total bacteria viable counts (TVC) detected in the water sources sampled in the three LGAs in showed that the highest bacteria count (204 cfu per mL) was recorded in S3-Depot well, Otukpo LGA in January 2023, and the lowest bacteria count (36 cfu per mL) was recorded in S2 in January 2023. Escherichia coli was the most prevalent bacteria as it occurred in all the sites sampled except S6- Ijami well, Ohimini LGA and S9- Amoke well, Apa LGA. Our finding based on the concentration of pollution indicating physico-chemical variables (e.g., EC, BOD5, and COD) showed the water sources studied in the three LGAs in Benue South were relatively perturbed. This was also confirmed by the prevalence of microbial loads which in most cases exceeded the minimum standard set by WHO for drinking water.

Seasonal Variation of Groundwater Quality in Bonny Island, Rivers State Nigeria

This study investigated the seasonal variations in physicochemical parameters, heavy metals, and petroleum hydrocarbons in groundwater samples collected in nine locations in Bonny Island, Rivers State Nigeria. The water samples for the dry season were collected in December and January while for the wet season, water samples were collected in July and October. A quantitative approach was employed, involving the collection of quantitative data through field sampling and laboratory analysis. Physicochemical parameters, including pH, electrical conductivity, dissolved oxygen, and nutrient levels, were measured using standard analytical techniques. Heavy metal concentrations (Fe, Cd, etc.) were determined using atomic absorption spectrophotometry, while petroleum hydrocarbons (total hydrocarbons and polycyclic aromatic hydrocarbons) were analyzed through solvent extraction and gas chromatography techniques. The study revealed significant seasonal variations in several parameters, with notable significant decreases in phosphate during the wet season and significant increases in chromium and cadmium levels during the dry season (p-value < 0.05). Petroleum hydrocarbon concentrations also exhibited seasonal fluctuations, potentially influenced by precipitation patterns, oil and gas activities, and accidental spills or leaks which were observed during the dry season.

In situ formation of an adsorbent using a mixture of ibuprofen and choline chloride for the extraction of Cu(II) and Cd(II) ions from water and fruit juice samples combined with dispersive liquid–liquid microextraction

In situ formation of an adsorbent using a mixture of ibuprofen and choline chloride for the extraction of Cu(II) and Cd(II) ions from water and fruit juice samples combined with dispersive liquid–liquid microextraction

Microplastics pollution in the Surma River, Bangladesh: A rising hazard to upstream water quality and aquatic life

The ecological health of freshwater rivers is deteriorating globally due to careless human activities, for instance, the emission of plastic garbage into the river. The current research was the first assessment of microplastics (MPs) pollution in water, sediment, and representative organisms (fish, crustacean, and bivalve) from the Surma River. Water, sediment, and organisms were sampled from six river sites (Site 1: Charkhai; Site 2: Golapganj; Site 3: Alampur; Site 4: Kazir Bazar; Site 5: Kanishail and Site 6: Lamakazi), and major water quality parameters were recorded during sampling. Thereafter, MPs in water, sediment, and organism samples were extracted, and then microscopically examined to categorize selected MPs types. The abundance of MPs, as well as size, and color distribution, were estimated. Polymer types were analyzed by ATR-FTIR, the color loss of MPs was recorded, the Pollution Load Index (PLI) was calculated, and the relationship between MPs and water quality parameters was analyzed. Sites 4 and 5 had comparatively poorer water quality than other sites. Microplastic fibers, fragments, and microbeads were consistently observed in water, sediment, and organisms. A substantial range of MPs in water, sediment, and organisms (37.33–686.67 items/L, 0.89–15.12 items/g, and 0.66–48.93 items/g, respectively) was recorded. There was a diverse color range, and MPs of <200 μm were prevalent in sampling areas. Six polymer types were identified by ATR-FTIR, namely Polyethylene (PE), Polyamide (PA), Polypropylene (PP), Cellulose acetate (CA), Polyethylene terephthalate (PET), and Polystyrene (PS), where PE (41%) was recognized as highly abundant. The highest PLI was documented in Site 4 followed by Site 5 both in water and sediment. Likewise, Sites 4 and 5 were substantially different from other study areas according to PCA. Overall, the pervasiveness of MPs was evident in the Surma River, which requires further attention and prompt actions.

Multifunctional 2D hemin-bridged MOF for the efficient removal and dual-mode detection of organophosphorus pesticides.

The high-residual and bioaccumulation property of organophosphorus pesticides (OPs) creates enormous risks towards the ecological environment and human health, promoting the research for smart adsorbents and detection methods. Herein, 2D hemin-bridged MOF nanozyme (2D-ZHM) was fabricated and applied tothe efficient removal and ultrasensitive dual-mode aptasensing of OPs. On the one hand, the prepared 2D-ZHM contained Zr-OH groups with high affinity for phosphate groups, endowing it with selective recognition and high adsorption capacity for OPs (285.7mgg-1 for glyphosate). On the other hand, the enhanced peroxidase-mimicking biocatalytic property of 2D-ZHM allowed rapid H2O2-directed transformation of 3,3',5,5'-tetramethylbenzidine to oxidic product, producing detectable colorimetric or photothermal signals. Using aptamers of specific recognition capacity, the rapid quantification of two typical OPs, glyphosate and omethoate, was realized with remarkable sensitivity and selectivity. The limit of detections (LODs) of glyphosate were 0.004nM and 0.02nM for colorimetric and photothermal methods, respectively, and the LODs of omethoate were 0.005nM and 0.04nM for colorimetric and photothermal methods, respectively. Theconstructed dual-mode aptasensing platform exhibited outstanding performance for monitoring OPs in water and fruit samples. This work provides a novel pathway to develop MOF-based artificial peroxidase and integrated platform for pollutant removal and multi-mode aptasensing.

Multi-metric biomonitoring of a seasonally flooded Baraila wetland using benthic macroinvertebrates as indicator organisms in the middle Ganga River Basin (Vaishali), India

ABSTRACT Human encroachment, urban and agricultural expansion, frequent droughts, eutrophication, infestation of weeds, and overexploitation of resources has predominantly impacted the water quality and biodiversity of the Baraila wetland. The present seasonal study has aimed to explore an under-researched subject of analyzing the water quality of the wetland through multi-metric biomonitoring approaches in 2022. A total of 24 water and benthic samples were collected from the four sampling locations. All the water parameters were within a suitable range to support diverse range of flora and fauna, except total suspended solids (TSS) and nutrient, indicating toward the impact of agricultural expansion in the wetland's area. Out of the 13 identified families of benthic macroinvertebrates, the semi-tolerant family of Viviparidae and Bithyniidae has dominated the wetland, with a relative abundance of 27.04 and 37.77%, respectively, in the comparative seasons. Moreover, the indices used in the study has categorized the wetland under moderately polluted condition. The Hierarchical Cluster Analysis (HCA) analysis has revealed the sensitivity toward organic pollution and habitat preferences has played major role in the species-specific assemblage of benthic community. The Mantel's correlogram further validates that the moderately polluted status of wetland has favored semi-tolerant to tolerant fauna in the wetland.

Heteroaggregation kinetics of nanoplastics and soot nanoparticles in aquatic environments

Heteroaggregation between polystyrene nanoplastics (PSNPs) and soot nanoparticles (STNPs) in aquatic environments may affect their fate and transport. This study investigated the effects of particle concentration ratio, electrolytes, pH, and humic acid on their heteroaggregation kinetics. The critical coagulation concentration (CCC) ranked CCCPSNPs > CCCPSNPs-STNPs > CCCSTNPs, indicating that heteroaggregation rates fell between homoaggregation rates. In NaCl solution, as the PSNPs/STNPs ratio decreased from 9/1 to 3/7, heteroaggregation rate decreased and CCCPSNPs-STNPs increased from 200 to 220 mM due to enhanced electrostatic repulsion. Outlier was observed at PSNPs/STNPs= 1/9, where CCCPSNPs-STNPs= 170 mM and homoaggregation of STNPs dominated. However, in CaCl2 solution where calcium bridged with STNPs, heteroaggregation rate increased and CCCPSNPs-STNPs decreased from 26 to 5 mM as the PSNPs/STNPs ratio decreasing from 9/1 to 1/9. In composite water samples, heteroaggregation occurred only at estuarine and marine salinities. Acidic condition promoted heteroaggregation via charge screening. Humic acid retarded or promoted heteroaggregation in NaCl or CaCl2 solutions by steric hindrance or calcium bridging, respectively. Other than van der Waals attraction and electrostatic repulsion, heteroaggregation was affected by steric hindrance, hydrophobic interactions, π − π interactions, and calcium bridging. The results highlight the role of black carbon on colloidal stability of PSNPs in aquatic environments.

Modeling approach for Ti3C2 MXene-based fluorescent aptasensor for amoxicillin biosensing in water matrices

Amoxicillin, a member of the penicillin family, is primarily utilized for the treatment of various bacterial infections affecting ears, nose, throat, urinary tract, and skin. Given its widespread application in medicine, agriculture, environment, and food industry, the precise and sensitive detection of amoxicillin is important. This study introduces a novel approach to developing a sensitive and selective fluorescent aptasensor relying on fluorescence resonance energy transfer (FRET) for the specific detection of amoxicillin. The carboxyfluorescein-labeled aptamer serves as a energy donor, while MXene functions as an energy acceptor, and acting as a quencher. To achieve optimal detection efficiency, a dual optimization strategy utilizing RSM-CCD and ANN-GA was used to fine-tune experimental conditions. The fluorescence measurements revealed an expansive linear range extending from 100 to 2400 ng mL−1, accompanied by an exceptionally low detection limit of 1.53 ng mL−1. Additionally, it shows an excellent selectivity towards amoxicillin over other antibiotics commonly found in water matrices. The aptasensor demonstrates good stability and reproducibility; effectiveness of the aptasensor was validated by testing in real water samples. This remarkable sensitivity and broad dynamic range affirm the efficacy aptasensor in accurately detecting varying concentrations of amoxicillin in wastewater bodies.

Machine learning and metagenomics identifies uncharacterized taxa inferred to drive biogeochemical cycles in a subtropical hypereutrophic estuary

Abstract Anthropogenic influences have drastically increased nutrient concentrations in many estuaries globally, and microbial communities have adapted to the resulting hypereutrophic ecosystems. However, our knowledge of the dominant microbial taxa and their potential functions in these ecosystems has remained sparse. Here, we study prokaryotic community dynamics in a temporal–spatial dataset, from a subtropical hypereutrophic estuary. Screening 54 water samples across brackish to marine sites revealed that nutrient concentrations and salinity best explained spatial community variations, whereas temperature and dissolved oxygen likely drive seasonal shifts. By combining short and long read sequencing data, we recovered 2459 metagenome-assembled genomes (MAGs), proposed new taxon names for previously uncharacterised lineages, and created an extensive, habitat specific genome reference database. Community profiling based on this genome reference database revealed a diverse prokaryotic community comprising 61 bacterial and 18 archaeal phyla, and resulted in an improved taxonomic resolution at lower ranks down to genus level. We found that the vast majority (61 out of 73) of abundant genus level taxa (&amp;gt;1% average) represented unnamed and novel lineages, and that all genera could be clearly separated into brackish and marine ecotypes with inferred habitat specific functions. Applying supervised machine learning and metabolic reconstruction, we identified several microbial indicator taxa responding directly or indirectly to elevated nitrate and total phosphorus concentrations. In conclusion, our analysis highlights the importance of improved taxonomic resolution, sheds light on the role of previously uncharacterised lineages in estuarine nutrient cycling, and identifies microbial indicators for nutrient levels crucial in estuary health assessments.

A Ratiometric Green Fluorescent Carbazole-bis(hydrazinobenzothiazole) Probe for the Selective Detection of Toxic Hg2+ Ions in Real Water Samples.

A dyad Carbazolyl-bis(hydrazinobenzothiazole) was designed to form a symmetrical structure that containing two-arm active binding sites facilitates coordination with Hg2+ ion. This sensor has imparted a colorimetric and fluorometric changes in presence of Hg2+ ions. The ligand showed a selective blue shift in presence of Hg2+even in co-existence with heavy metal ions with luminescence change from colorless to blue and colorless to green under day light. Enhanced Intramolecular charge transfer process is responsible for fluorescence transformation when ligand interacts with Hg2+ ion. The emission spectra showed a ratiometric response to increasing addition of Hg2+ ions. The sensor is capable of detecting above the lower concentration of 6.8025 × 10-8 M. The fluorescence efficiency of CBT-2 with Hg2+ ion is quite stable under different co-metal ions and wide range of pH 6 to 9. The sensor CBT-2 forms a 1:1 stoichiometric complex with Hg2+ ions and the binding nature is confirmed from the 1H-NMR, FTIR, and mass spectroscopic studies. The sensor CBT-2 and its Hg2+ complex possess good binding nature to protein in Bovine Serum Albumin which could be good in biological applications. Additionally, wedevelop a practical application in real water sample analysis and electrochemical detection viaoxidation potential discrimination.

Validation of a Loop-Mediated Isothermal Amplification-Based Kit for the Detection of Legionella pneumophila in Environmental Samples According to ISO/TS 12869:2012

Legionella pneumophila is a freshwater opportunistic pathogen and the leading cause of severe pneumonia known as Legionnaires’ disease. It can be found in all water systems and survives in biofilms, free-living amoebae, and a wide variety of facilities, such as air conditioning and showers in hospitals, hotels and spas. The reference cultural method allows for the isolation and identification in many days, and in addition, it does not detect viable but rather non-culturable bacteria, increasing the risk of infection. In this context, a new LAMP-based (loop-mediated isothermal amplification) kit was developed, allowing for the rapid, sensitive, and labor-saving detection of L. pneumophila. The kit, “Legionella pneumophila Glow”, was validated according to ISO/TS 12869:2012, testing sensitivity, inclusivity and exclusivity, and kit robustness. Sensitivity showed that the “Legionella pneumophila Glow” kit can detect up to 28 plasmid copies/µL. Robustness tests showed consistent results, with both contamination levels and the matrices used giving reproducible results. Furthermore, real samples were evaluated to compare the performance of the two methods. The LAMP kit “Legionella pneumophila Glow” proved a useful option for the rapid, efficient, and labor-saving screening of different typologies of water samples, offering significant advantages over the traditional method, as it is characterized by a high sensitivity, ease of use for laboratory testing, and a large reduction in analysis time, making it an asset to official controls.

A Zn/Cd/Ni Metal-Organic Framework-Based Solid and Flexible Fluoroprobes for Highly Selective Detection of 4-Nitroaniline in Real Water Samples.

The combination of diazabicyclic compound i.e. 1,4-diazabicyclo[2.2.2]octane (DABCO) and dicarboxylate linker 1,4-dicarboxylic acid are employed to self-assemble with three divalent metal ions such as Zn2+, Cd2+, Ni2+ led to the formation of highly stable pillar layered luminescent metal-organic frameworks. The emissive response of as-synthesized MOFs was studied in organic solvents with different functionalities resulting in the development of fluoroprobes having excellent recognition ability for 4-nitroaniline with detection limit upto micromolar. All the MOFs display a good linear relation between the fluorescence intensity and concentration of 4-NA in the range of 10-90µmol L-1. The values of Ksv for Zn-MOF, Cd-MOF, and Ni-MOF are found to be 1.75 × 104mol-1L, 1.25 × 104mol-1L, and 28.0 × 104mol-1L, respectively. The calculated detection limit values are 19.7µmol L-1, 27.6µmol L-1, and 1.19µmol L-1 respectively. Moreover, the study was further extended to fabricate the solid membrane-based fluoroprobe using a linear chitosan polysaccharide and act as an efficient solid fluoroprobe for the detection of 4-NA. This proposed synthesis of polymeric membrane facilitates the MOF@chitosan fluorophore to transfer its fluorescence-emissive nature to a solid state.

Pepper mild mottle virus intended for use as a process indicator for drinking water treatment: Present forms and quantitative relations to norovirus and rotavirus in surface water

Pepper mild mottle virus (PMMoV) has been proposed as a potential indicator of human enteric viruses in environmental water and for viral removal during drinking water treatment. To investigate the occurrence and present forms of PMMoV and quantitative relations to norovirus GII and rotavirus A (RVA) in surface waters, 147 source water samples were collected from 21 drinking water treatment plants (DWTPs) in Japan between January 2018 and January 2021, and the concentrations of viruses in suspended and dissolved fractions were measured using real-time RT-PCR. PMMoV was detected in 81–100 % of samples in each sample month and observed concentrations ranged from 3.0 to 7.0 log10 copies/L. The concentrations of PMMoV were higher in dissolved fraction compared to suspended fractions, while different partitioning was observed for NoV GII depending on seasons. The concentrations of PMMoV were basically higher than those of norovirus GII (1.9−5.3 log10 copies/L) and RVA (1.9−6.6 log10 copies/L), while in 18 samples, RVA presented higher concentrations than PMMoV. Partial regions of VP7, VP4, and VP6 of the RVA in the 18 samples were amplified using nested PCR, and the genotypes were determined using an amplicon-based next-generation sequencing approach. We found that these source water samples included not only human RVA but also various animal RVA and high genetic diversity due to the existence of animal RVA was associated with a higher RVA concentration than PMMoV. Our findings suggest that PMMoV can be used as an indicator of norovirus GII and human RVA in drinking water sources and that the indicator performance should be evaluated by comparing to zoonotic viruses as well as human viruses.