Tap Water Samples Research Articles

A selective and sensitive mercury sensor for drinking water based on fluorescence quenching of pure rhodamine B

The escalating threat of industrial pollutants, particularly heavy metals, in water sources poses a significant risk to global populations. Among these heavy metals, mercury stands out as a severe contaminant with detrimental health implications. This paper introduces a novel and efficient method for the selective detection of mercury ions in drinking water, employing laser-induced fluorescence with pure rhodamine B as the sensing probe. The method achieves a low detection limit of 7 ppb, closely approaching the World Health Organization’s maximum permissible limit. The simplicity of the procedure, coupled with the use of pure rhodamine B, distinguishes this approach from others relying on complex chemical procedures and derivatives of rhodamine B. The sensing mechanism involves the fluorescence quenching of rhodamine B due to complex formation with tetraiodomercurate. Noteworthy is the method’s selectivity, demonstrated by its resistance to interference from common ions present in water (e.g. Magnesium, calcium, sodium, and potassium), ensuring accurate detection of mercury ions. Extensive testing with tap water samples, considering potential interference, validates the robustness of the sensor, with recovery percentages of 99.25% and 109.2%. In summary, this study contributes a practical solution to the critical challenge of mercury detection in drinking water, addressing issues of sensitivity, selectivity, and on-site applicability. The proposed method holds promise for widespread implementation, enhancing efforts to safeguard public health and ensure the safety of water resources.

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

A nationwide survey of inorganic components of tap water all over Japan was conducted from 2019 to 2024. In this survey, 1564 tap water samples were collected, and an additional 194 tap water samples were collected from 33 other countries. The water samples were analyzed for 27 dissolved inorganic components, with a primary focus on the distribution of major and trace components, including Ca, Mg, K, Na, Cl−, NO3−, SO42−, total-hardness, Al, Fe, Cu, Mn, and Zn. The Japanese tap water hardness was 50.5 ± 30.2 (± 1σ SD) mg/L, classified as soft water according to the World Health Organization (WHO) classification. The average content of each major component in Japanese tap water tended to be lower than those in other countries. Furthermore, Piper trilinear diagrams were used to categorize Japanese tap water types. The dominating water types were the Ca–HCO3 and mixed types, which had a nationwide distribution. Japanese tap water generally complied with Japanese and WHO drinking water criteria, with only 1% (17/1564 sites) of the samples exceeding water quality standards. Observations of water quality changes for 2 years at three household faucets revealed that fluctuations in major components and trace metals (Al, Fe, Cu, Mn, and Zn) varied in different patterns. This suggests that the behavior of trace metal elements is influenced by local infrastructure, such as supply pipes, distinct from the variability in source water quality.

A sensitive aptasensor mediated by gold nanoparticles/metal organic framework lattice for detection of Pb2+ ion in marine products

Herein, an enzyme-free fluorescent aptasensor was introduced for the ultrasensitive quantification of lead (Pb2+) ion as a hazardous pollutant of the environment and foodstuffs. A nanocomposite of zeolitic imidazolate frameworks-8 and gold nanoparticles (ZIF-8@AuNPs) was utilized as an efficient quencher of the fluorescence intensity of carboxyfluorescein (FAM) signal reporter. The establishment of a hybrid structure between attached aptamer on ZIF-8@AuNPs nanocomposite, and its FAM-tagged complementary (CP) strand decreased the fluorescence response. The preferential binding between the aptamer and Pb2+ released CP strands, which retrieved the fluorescence signal. The aptasensor could assess Pb2+ in the linear concentration range of 1 pM-1 nM with a detection limit (LOD) of 0.24 pM. Besides, it could quantify Pb2+ in various samples, including fish, shrimp, tap water, milk, and serum samples. The developed aptasensor with the superiorities of easiness, cost-effectiveness, easy-to-operate, and rapidness is promising for controlling marine foodstuff safety.

Electrochemical sensor based on Y-shaped DNA by “one-pot” method for mercury detection

A DNA electrochemical sensor based on Y-shaped DNA probes was successfully designed for Hg2+ detection. The sensor was modified with carbon self-doping graphite-like carbon nitride (C-g-C3N4) and electrodeposited gold nanoparticles (EAu) to enhance conductivity and enrich the binding sites for DNA. DNA probe (S1) binded on the modified electrode via –SH, forming a stable Y-shaped DNA double helix structure with probe S2 and probe S3 anchoring on gold nanoparticles (nanoAu) in the presence of Hg2+ solution. The Y-shaped DNA duplex, with its tight and nondeformable rigid structure, created well-defined stereoscopic reaction areas and efficiently captures Hg2+ due to its structural differences, thereby improving the signal response. Moreover, larger amounts of methyleneblue (MB) could be loaded to provide adequate electrochemical response signal. The proposed sensor possessing signal amplification ability displayed a linear relationship between the square wave voltammetry (SWV) peak currents. Under the optimal conditions, Hg2+ could be detected in the range from 5000.0 to 5.0 nM with a detection limit of 8.5 pM. The sensor was also tested with tap water, river and medical wastewater samples. It showed the good recovery and accuracy and represented a promising method for Hg2+ detection.

Radiation protection for Gabes phosphate area residents: Assessing natural radioactivity in soil and potable water samples

Phosphate mining activities are recognized to be one of various industrial processes generating enhanced Naturally Occurring Radioactive Materials (NORM) by introducing natural radionuclides into the surrounding soils and water bodies, posing a risk to human health.This study was carried out to assess the level of natural radionuclides in soils and potable waters collected from the phosphate area of Gabes city, located in southeastern Tunisia, and to evaluate radiation protection measures by estimating radiological health hazard parameters. Gamma spectrometry system employing an HPGe detector was used in this study to assess 40K, 232Th and 226Ra activity concentration in soils. The average values were found to be 163.7, 14.5, and 7.7 Bq kg−1, respectively, which were lower than worldwide average values. The radiological hazard parameters assessed in this study were radium equivalent activity (Ra-eq), external hazard index (Hex), external gamma absorbed rate (GDR), external annual effective dose (Deff) and excess lifetime cancer risk (ELCR). The calculated average values of the above-mentioned parameters were of 41 Bq kg−1, 0.1, 20.2 nGy h−1, 24.8 μSv y−1 and 8.7 × 10−5 all of which were found to be below their permissible standards.For potable water samples, the activity concentrations of radium were analyzed using an HPGe detector and those of uranium were determined by alpha spectrometry. The average activity concentrations of uranium and radium isotopes in underground water samples were found to be higher than those obtained in tap water samples. For both types of water, the average values for all radionuclides were found to be below their respective reference limits.The annual ingestion effective doses were also estimated in this study. The estimated average values for infant and children for underground water samples were higher than the permissible limit of 100 μSv y−1 set by WHO. The 226Ra was the main contributor to the effective doses for different age categories, followed by 228Ra.

Sensitive and reliable hybrid nanosensor (Co2+-CDs@R-CDs) for ratiometric fluorescent and colorimetric detecting NO2−

A ratiometric fluorescent and colorimetric detecting assay for NO2− was realized by a hybrid nanosensor (Co2+-CDs@R-CDs) utilizing firstly through the redox reaction of nitrite (NO2−) with Co2+, of which the hybrid nanosensor Co2+-CDs@R-CDs was fabricated by Co2+-doped carbon dots (Co2+-CDs) and a reference of red-emitting carbon dots (R-CDs). The ratiometric fluorescent linear detection range of NO2− was 2.5–45 μM and the limit of detection (LOD) was 0.068 μM with the response time of 120 s. While, the colorimetric linear detection range of NO2− was 2.5–60 μM and the LOD was 0.075 μM. In addition, a portable smartphone system which could measure the R (red), G (green), and B (blue) values of the fluorescence and the visible color of the coated Co2+-CDs@R-CDs paper strip-based sensor had also been developed and successfully applied to detect NO2− in sausage, pickles and tap water samples.

Gold nanoparticles decorated magnetic nanozyme for colorimetric detection of mercury (II) ions via enhanced peroxidase-like activity

Mercury is one of the heavy metal ions that are released to the environment through various means including anthropogenic pollution. A very low dose of mercury in environmental systems such as water can lead to debilitating effects on the health of humans and animals, if consumed untreated. To reduce this effect, it is critical to develop a simple, non-expensive, and non-sophisticated detection and monitoring system of mercury. Here, we report a simple colorimetric method based on the peroxidase-like activity of AuNPs/ZnO/Fe3O4. Different characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and surface-enhanced Raman spectroscopy (SERS) were used to investigate the successful formation of these composites. The formation of AuNPs was assisted by ZnO. The low Km value (0.7368 mM) obtained from the kinetic study of the catalytic oxidation of 3, 3′, 5, 5′ − Tetramethylbenzidine (TMB) showed strong affinity of TMB to AgNPs/ZnO/Fe3O4. The peroxidase-like activity of AgNPs/ZnO/Fe3O4, was further enhanced in the presence of mercury (II). The absorption intensities of the resulting oxidized TMB (oxTMB) increased linearly in a concentration range of 0.05 – 20 µM. The method also exhibited high selectivity to mercury (II) ions. The limit of detection (LOD) in this linear range was found to be 28.1 nM. The feasibility of the method in determination of mercury (II) ions from real samples was confirmed from high recovery rates in tap water samples. The method shows a great potential for determination of mercury (II) ions in environmental samples.

Assessment of drinking water quality using Water Quality Index and synthetic pollution index in urban areas of mega city Lahore: a GIS-based approach

The aim of the present study was to assess the drinking water quality in the selected urban areas of Lahore and to comprehend the public health status by addressing the basic drinking water quality parameters. Total 50 tap water samples were collected from groundwater in the two selected areas of district Lahore i.e., Gulshan-e-Ravi (site 1) and Samanabad (site 2). Water samples were analyzed in the laboratory to elucidate physico-chemical parameters including pH, turbidity, temperature, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), total hardness, magnesium hardness, and calcium hardness. These physico-chemical parameters were used to examine the Water Quality Index (WQI) and Synthetic Pollution Index (SPI) in order to characterize the water quality. Results of th selected physico-chemical parameters were compared with World Health Organization (WHO) guidelines to determine the quality of drinking water. A GIS-based approach was used for mapping water quality, WQI, and SPI. Results of the present study revealed that the average value of temperature, pH, and DO of both study sites were within the WHO guidelines of 23.5 °C, 7.7, and 6.9 mg/L, respectively. The TDS level of site 1 was 192.56 mg/L (within WHO guidelines) and whereas, in site 2 it was found 612.84 mg/L (higher than WHO guidelines), respectively. Calcium hardness of site 1 and site 2 was observed within the range from 25.04 to 65.732 mg/L but, magnesium hardness values were higher than WHO guidelines. The major reason for poor water quality is old, worn-out water supply pipelines and improper waste disposal in the selected areas. The average WQI was found as 59.66 for site 1 and 77.30 for site 2. Results showed that the quality of the water was classified as “poor” for site 1 and “very poor “ for site 2. There is a need to address the problem of poor water quality and also raise the public awareness about the quality of drinking water and its associated health impacts.

A dual-signaling surface-enhanced Raman spectroscopy ratiometric strategy for ultrasensitive Hg2+ detection based on Au@Ag/COF composites

Heavy metal ion pollution poses significant risks to human health and ecological systems, and its monitoring is important. A sensitive and accurate surface-enhanced Raman spectroscopy (SERS) detection assay for Hg2+ was developed using Au@Ag/COF substrates and Y-shaped DNA labeled with two Raman reporters. The Au@Ag NPs in the COF produced robust and uniform E-fields, improving their detection reproducibility. The Y-shaped DNA design increased sensitivity with a low detection limit of 5.0 × 10−16 M by bringing the Raman reporter closer to the substrate surface. Additionally, the use of two Raman reporters allowed for a ratiometric method, improving detection accuracy by detecting both “signal-off” and “signal-on” signals. This selective sensor exhibited excellent recovery in river water, tap water, and milk samples, showcasing its robust biosensing capability for the detection of Hg2+ and its potential for sensing other heavy-metal ions in food and environmental applications.

Single-atom iodine anchored layered graphitic carbon nitride: Dual functional Electrocatalyst for acetaminophen detection and oxygen evolution reaction

Developing highly effective bifunctional electrocatalysts for acetaminophen (ACP) detection and oxygen evolution reaction (OER) is significant and challenging. Thermal decomposition methods were used to create a high-radius and high electronegative iodine doped porous graphitic carbon nitride (IO-gCN) bifunctional electrocatalyst in here. The synergistic effect of pores nature, active sites and nanosheet-like structure, IO-gCN exhibit better ACP detection and OER activity. Under optimized conditions, IO-gCN detection limits (LOD) for ACP is 4.6 nM with a linear range of 0.2–80 μM and sensitivity is 3.234 μA μM−1 cm−2. The proposed nanosheets decorated disposable screen-printed carbon electrode (SPCE) also applied real samples (tap water and human urine sample) to obtained better recovery results. The electrochemical linear sweep voltammetry (LSV) exhibited a lower over potential (270 mV) and small Tafel slope value (144 mV/dec) at 10 mA/cm2 for IO-2 (2 wt% doped gCN) nanosheets under alkaline medium (1 M KOH). Additionally, the chronoamperometry (CA) test and the cyclic voltammetry 3000th cycle test both produced results for long-term stability and hybrid stability. This study offers a straightforward and esoteric method for creating bifunctional electrocatalysts that are free of metal.

Smartphone-assisted chemosensor based on thiocarbohydrazide Schiff base for selective detection of Hg2+ and Cu2+ ions

A simple and sensitive thiocarbohydrazide Schiff base colorimetric chemosensor (L) was synthesized, and characterized by FTIR, 1H NMR, TOF-MS, and elemental analyses. UV–vis absorption spectra of L in CH3CN:H2O (9:1, v/v) showed a highly selective absorption enhancement response towards Hg2+ and Cu2+ ions, accompanied by distinct color changes from colorless to yellow. The binding stoichiometry of chemosensor L and related metal ions was 2:1 and the binding constant was 2.6 × 105 M−1 for Hg2+ and 2.6 × 104 M−1 for Cu2+. The detection limits for Hg2+ and Cu2+ ions were 0.11 and 0.18 µM, respectively. The effective naked eye color change of L depending on Hg2+ and Cu2+ concentration was integrated with smartphone for real-time applications of chemosensor. Finally, L was successfully applied to determine of Hg2+ and Cu2+ ions in tap water, drinking water, and river water samples.

Rational design and application of broad-spectrum antibodies for Bt Cry toxins determination

Using the amino acid sequences and analysis of selected known structures of Bt Cry toxins, Cry1Ab, Cry1Ac, Cry1Ah, Cry1B, Cry1C and Cry1F we specifically designed immunogens. After antibodies selection, broad-spectrum polyclonal antibodies (pAbs) and monoclonal antibody (namely 1A0-mAb) were obtained from rabbit and mouse, respectively. The produced pAbs displayed broad spectrum activity by recognizing Cry1 toxin, Cry2Aa, Cry2Ab and Cry3Aa with half maximal inhibitory concentration (IC50) values of 0.12–9.86 μg/mL. Similarly, 1A0-mAb showed broad spectrum activity, recognizing all of the above Cry protein (IC50 values of 4.66–20.46 μg/mL) with the exception of Cry2Aa. Using optimizations studies, 1A10-mAb was used as a capture antibody and pAbs as detection antibody. Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISAs) were established for Cry1 toxin, Cry2Ab and Cry3Aa with the limit of detection (LOD) values of 2.36–36.37 ng/mL, respectively. The present DAS-ELISAs had good accuracy and precisions for the determination of Cry toxin spiked tap water, corn, rice, soybeans and soil samples. In conclusion, the present study has successfully obtained broad-spectrum pAbs and mAb. Furthermore, the generated pAbs- and mAb-based DAS-ELISAs protocol can potentially be used for the broad-spectrum monitoring of eight common subtypes of Bt Cry toxins residues in food and environmental samples.

Development of electrochemical sensors based on silver nanoparticles electrodeposited on gold screen-printed electrodes: application to nitrate trace analysis in water

Abstract. A simple, reusable and sensitive electrochemical sensor based on a gold screen-printed electrode modified with silver nanoparticles has been developed for the detection of nitrate in water. Scanning electron microscopy, square wave voltammetry and electrochemical impedance spectroscopy were used to characterize the modification of the electrode surface. The modified electrode with different silver nanoparticle loadings was also tested, as well as the influence of scan rate on the reduction of nitrate. The sensor exhibited a wide linear response to nitrate from 100 to 1500 µM and a detection limit of 7.7 µM, which is significantly less than the maximum contaminant level admitted in drinking water (800 µM). The reproducibility, repeatability and selectivity of the sensor have also been examined. The suitability of the proposed sensor for real sample detection was successfully demonstrated via recovery studies performed in spiked tap water samples. The proposed approach was used to determine nitrate in freshwater, and the results were in good agreement with those obtained from a commercial nitrate sensor. These advantages make the developed sensor a promising alternative approach for integration into an online monitoring system for water monitoring.

Gold nanoparticles capped with α-cyclodextrin for dual colorimetric sensing of Fe3+ and Cr3+ in tap water

Abstract A rapid colorimetric assay for the dual detection of Fe3+ and Cr3+ using gold nanoparticles (AuNPs) capped with α-cyclodextrin was developed. The synthesized AuNPs produced a red wine color with a particle size of 8.60 ± 1.55 nm and were stable for 9 months. Detection of Fe3+ and Cr3+ changed the color of the AuNPs solution to bluish purple with a detection time of <1 and 10 min, respectively. Reaction of the AuNPs with Fe3+ and Cr3+ also increased the particle size of the AuNPs to 16.18 ± 2.28 nm and 17.33 ± 1.71 nm, respectively. Characterization of the AuNPs using Fourier-transform infrared spectroscopy and X-ray diffraction showed that the presence of Fe3+ would damage the structure of the AuNPs, whereas Cr3+ would not. This colorimetric sensor is sensitive toward Fe3+ and Cr3+ with limits of detection of 265.92 and 430.80 μg/L, respectively. The dual ion sensing ability of the AuNPs was also assessed by individually detecting Fe3+ and Cr3+ in tap water samples in South Tangerang, Banten, Indonesia.

Tannic Acid-Decorated Bimetallic Copper-Gold Nanoparticles with High Catalytic Activity for the Degradation of 4-Nitrophenol and Rhodamine B.

In this study, tannic acid (TA) was applied as a stabilizing agent for synthesizing bimetallic copper-gold (CuAu) nanoparticles. Cu(NO3)2 and NaAuCl4 were used as the sources of copper and gold ions, respectively, and NaBH4 was employed as a reducing agent. The prepared TA-CuAu nanoparticles were extensively characterized via ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and zeta potential analyses. To evaluate their catalytic activity, the TA-CuAu nanoparticles and NaBH4 were applied in the degradation of 4-nitrophenol (4-NP) and rhodamine B (RB) individually and in a mixture. The individual degradation of 4-NP and RB was completed within 10 min, and the apparent rate constants were calculated as 0.3046 and 0.2628 min-1, respectively, emphasizing the efficient catalytic activity of the TA-CuAu nanoparticles. Additionally, controlled experiments were performed for the degradation of 4-NP and RB in the absence of catalysts or NaBH4 to investigate the kinetic feasibility of the catalytic reactions. A mixture of 4-NP and RB was successfully degraded within 10 min using the TA-CuAu nanoparticles as catalysts. Furthermore, the reuse of the catalysts after five successive cycles demonstrates an outstanding performance with no significant loss in the catalytic activity. Finally, the successful treatment of the tap and lake water samples spiked with 4-NP and RB using the TA-CuAu nanoparticles further confirmed their application potential as catalysts in environmental water remediation.

Microplastic accumulation, morpho-polymer characterization, and dietary exposure in urban tap water of a developing nation

The recent detection of microplastics (MPs) in a large number of commercially important food items and beverages, including tap water, has drawn significant attention because of direct exposure and negative health effects on humans. Nevertheless, there is insufficient information on microplastic contamination in the tap water of developing countries. In the present study, we primarily analyzed supplied tap water samples from four major cities in Bangladesh to determine and characterize MPs using a stereomicroscope and Fourier transform infrared spectroscopy (FTIR). Several indices were employed to calculate human health exposures to microplastics. MPs were found in all of the water samples tested, with an overall mean of 35.33 ± 19.55 particles/L. The results of this study diverge from those of comparable research conducted globally, revealing that tap water in Bangladesh exhibited higher levels of contamination compared to other nations. MPs were found in three different shapes (fibers, fragments, and films), with fibers dominating the samples (96.2%), and 98.1% of the microplastics were less than 0.5 mm in size. Six different colors of MPs were observed, and transparent particles were dominant (63.9% of all observed MPs). FTIR infrared spectrum analysis revealed two major types of polymers: low-density polyethylene (LDPE) and high-density polyethylene (HDPE). The projected daily consumption of microplastics was determined to be 2.65 particles per person per day, raising potential concerns for human health. The findings show that the treatment process of the water supply system is inadequate. Additionally, the sources of microplastics in tap water may come from where the water was collected for treatment and may be linked to a variety of anthropogenic activities, such as urbanization, sewage discharge, industrial waste disposal, and runoff from catchment areas.

Electrochemical Determination of Catechol Using a Disposable Printed Electrode with Conductive Ink Based on Graphite and Carbon Black

Catechol (CT) is a phenolic compound widely used in various industrial sectors, but it is toxic; thus, there is a need for methods that aim to identify and quantify the existence of residues of this material in the environment. In this study a disposable printed electrochemical sensor was developed as an effective alternative for determining CT in water samples. The electrode, called SPEC, was manufactured using the screen-printing method using polyethylene terephthalate (PET) as a support, in which a conductive ink based on carbonaceous materials was used to print the working and auxiliary electrodes and a silver/silver chloride of ink on the reference electrode. The optimal ratio for the conductive ink was 6.25% carbon black, 35.42% graphite, and 58.33% nail polish. The ink obtained was characterized by scanning electron microscopy (SEM). The assessment of the effect of pH on the redox process showed Nernstian behavior (0.057 V pH−1), indicating that the process involves the same number of protons and electrons. Under optimized conditions, with 0.2 mol L−1 acetate buffer at pH 5.0, and by square wave voltammetry, the sensor presented sensitivity values of 0.31 μA L μmol−1, a detection limit of 5.96 μmol L−1, and a quantification limit of 19.87 μmol L−1. The sensor was applied to determine CT in tap water samples, and the results showed recoveries between 97.95 and 100.17%.

Novel benzothiazole-pyrazoline-styrene hybrid for ultrasensitive detection of Hg(II) ions: Synthesis and chemosensor evaluation.

Water pollution has become a serious issue, and mercury(II) ion (Hg(II)) is highly toxic even at low concentrations. Therefore, Hg(II) concentration should be strictly monitored. This study evaluated pyrazoline compounds as fluorescence chemosensor agents for Hg(II) detection. These compounds were prepared from vanillin via etherification, Claisen-Schmidt, and cyclocondensation reactions, to yield benzothiazole-pyrazoline-styrene hybrid compounds. The hybrid compound without styrene was successfully synthesized in 97.70% yield with limit of detection (LoD) and limit of quantification (LoQ) values of 323.5 and 1078 μM, respectively. Conversely, the hybrid compound was produced in 97.29% yield with the LoD and LoQ values of 8.94 and 29.79 nM, respectively. Further spectroscopic investigations revealed that Hg(II) ions can either chelate with three nitrogen of pyridine, pyrazoline, and benzothiazole structures or two oxygen of vanillin and styrene. Furthermore, the hybrid compound was successfully applied in the direct quantification of Hg(II) ions in tap and underground water samples with a validity of 91.63% and 86.08%, respectively, compared with mercury analyzer measurement. The regeneration of pyrazoline was also easily achieved via the addition of an ethylenediaminetetraacetic acid solution. These findings show the promising application of the benzothiazole-pyrazoline-styrene hybrid compound for Hg(II) monitoring in real environmental samples.

Ratiometric fluorescence detection of tetracycline in milk and tap water with smartphone assistance for visual pH sensing using innovative dual-emissive phosphorus-doped carbon dots

Tetracycline (TC) is a common antibiotic that poses risks to human and animal health when present in samples. pH is a crucial parameter for assessing water quality and food safety. The innovative ratiometric probe, designed based on dual-emissive phosphorus-doped carbon dots (DE-P-CDs), was synthesized through a green hydrothermal process. The sensor exhibited high analytical performance toward TC detection with a LOD of 5.78 μM and 6.18 μM, respectively, and visual pH detection. Furthermore, the DE-P-CDs were employed for visual pH sensing, with the solution color smoothly changing with variations in pH. The color transitioned from red to orange, green to dark green, and blue to dark blue, facilitating easy visual observation. This probe proves to be a versatile tool for detecting TC in milk and tap water samples, with visual capabilities for pH. Two metric tools which were AGREE and BAGI were also used to evaluate the method's greenness. The evaluation affirmed its outstanding environmental friendliness. It represents a valuable contribution to the fields of analytical chemistry, food, and environmental monitoring.

An affordable and green voltammetric approach for the determination of sotalol in biological, environmental, and pharmaceutical samples

AbstractThis work outlines the development of a voltammetric method for a sensitive, rapid, and environmentally friendly determination of the antihypertensive sotalol (SOT) in several sample types employing the anodically pretreated boron‐doped diamond electrode. Cyclic voltammograms of SOT presented a well‐defined irreversible oxidation peak at 1.21 V (Ag/AgCl (3.0 mol L−1 KCl)) in Britton–Robinson buffer solution (pH 3.0). Figures of merits recommended by the validation guidelines were evaluated for the validation of the present method. Employing differential pulse voltammetry linearity of SOT was obtained in the concentration range of 0.39–4.22 μmol L−1 in 0.1 mol L−1 H2SO4 solution, with a limit of detection of 0.031 μmol L−1. The selectivity of the method was assessed against interferers and show relative standard deviation (RSD) values lower than 6 %. Recovery tests yielded percentages ranging from 93 % to 96 % in urine sample and from 100 % to 107 % in tap water sample. The proposed method was successfully applied in pharmaceutical, environmental, and biological samples offering a suitable green analytical chemistry profile.