Environmental Water Samples Research Articles

Preparation of magnetic coconut clothing biochar for extracting neonicotinoid insecticides from environmental water samples

In this study, the magnetic coconut clothing biochar hybrid materials were successfully prepared by in-situ method. The obtained magnetic biochar was characterized in detail by using series of analytical techniques. The results showed that the magnetic hybrid materials presented alveolate network structures with abundant large pores and good magnetic separation ability with Fe3O4 nanoparticles obviously attached on the surface of biochar. The magnetic biochar hybrid materials were used as adsorbents during magnetic solid-phase extraction process for extracting neonicotinoid insecticides from environmental water samples. The adsorption and desorption parameters (adsorption time, elution condition, sample volume, sample pH) affecting magnetic solid-phase extraction efficiency were carefully investigated. Under the optimum conditions (adsorption for 15 min, 5 % formic acid-acetonitrile as elution condition, 50 mL of sample volume, 15 mg of magnetic biochar, pH at 5.0), the magnetic solid-phase extraction process based on magnetic coconut clothing biochar hybrid materials coupled with high performance liquid chromatography tandem mass spectrometry for enriching and detecting neonicotinoid insecticides in environmental water samples was established. The good linear relationship in the range of 0.5–200 ng mL−1 with correlation coefficients greater than 0.9989 and the lower limits of detection (0.0017–0.0069 ng·mL−1) were obtained. The recovery in the spiked water samples was in the range of 68.6 %-104.0 % with relative standard deviation from 0.4 % to 9.3 %. These results demonstrated that the established method was highly sensitive, convenient and repeatable for directly analyzing trace neonicotinoid insecticides in environmental water samples. More importantly, the novel biochar from coconut clothing was introduced into sample pretreatment to enrich trace organic pollutants.

Au nanoparticles decorated graphitic carbon nitride nanosheets as a sensitive and selective fluorescence probe for Fe3+ and dichromate ions in aqueous medium

Graphitic carbon nitride mutated with metal nanoparticles has captivated great interest as an effective fluorescent sensor for the detection of harmful ions present in water. In the present work, bulk-gCN was synthesized using melamine as precursor, and further Au-gCN nanocomposite were fabricated via in-situ direct reduction deposition method. The structural, morphological, compositional, stability and optical properties of bulk gCN and Au-gCN nanocomposite were examined using various scattering and spectroscopic techniques such as HRTEM, XPS, XRD and SEM. The synthesized bulk gCN straggles during selectivity studies with different cations and anions because of its uneven surface morphology, however in Au-gCN gold nanoparticles are uniformly distributed on the gCN sheets which results in its enhanced selectivity over bulk gCN. This leads to the fabrication of an optical sensor for Fe3+ and Cr2O72− ions with limit of detection of 4.62 and 2.77 μM, respectively. The sensing of Fe3+ ions corresponds to the photoinduced electron transfer (PET) mechanism, while the detection of chromate species is associated with an inner filter effect (IFE). The practical applicability of the sensor was also evaluated for different environmental water samples. The high stability, sensitivity, and specificity of Au-gCN nanocomposite make it a potential fluorescent probe for Fe3+ and Cr2O72− ions in water samples.

A highly specific colorimetric fluorescent probe for rapid detection of hypobromous acid and its application in the environment

The highly reactive hypobromous acid (HOBr), which is generated after chlorination process of tap water, acts as a precursor of toxic brominated disinfection by-products (Br-DBPs) and further reacts with organic matter. In addition, HOBr produced from the oxidation of Br− during the degradation of pollutants by peroxymonosulfate (PMS, HSO5−) can be considered as the cause of the expedited degradation of pollutants. Therefore, it is particularly important to detect HOBr level in the water environment. Resazurin was selected as a fluorescent probe for selective recognition of HOBr in the water environment. The probe exhibited excellent spectral performance and showed high sensitivity to HOBr (LOD = 515 nM). This method has a relatively ideal recovery rate for HOBr detection in environmental water samples. Furthermore, the HOBr production during the chlorination disinfection process was simulated and the HOBr generated from this process was detected by the probe. Importantly, the process of HOBr recognition by the probe is accompanied by the change of color. Based on this, the relationship between the change of color B/G value and HOBr concentration was successfully constructed. The probe was loaded on the filter paper to make a test strip, which was utilized to the detection of HOBr. Collectively, this work provided a promising and powerful method for HOBr detection in the environment.

Rapid and on-site detection of bisulfite via a NIR fluorescent probe: A case study on the emission wavelength of probes with different quinolinium as electron-withdrawing groups

The emission of venenous sulfur dioxide (SO2) and its derivatives from industrial applications such as coking, transportation and food processing has caused great concern about public health and environmental quality. Probes that enable sensitivity and specificity to detect SO2 derivatives play a crucial role in its regulations and finally mitigating its environmental and health impacts, but fluorescent probes that can accurately, rapidly and on-site detect SO2 derivatives in foodstuffs and environmental systems rarely reported. Herein, a near-infrared (NIR) fluorescent probe (ZTX) for the ratiometric response of bisulfite (HSO3−) was designed and synthesized by regulating the structure of high-performance HSO3− fluorescent probe SL previously reported by us based on structural analyses, theoretical calculations and related literature reports. The Michael addition reaction between the electronic-deficient C=C bond and HSO3− destroys ZTX's π-conjugation system and blocks its intramolecular charge transfer (ICT) process, resulting in a significant fading of the fuchsia solution and the bluish-purple fluorescence turned light blue fluorescence. Fluorescent imaging of HSO3− in live animals utilizing ZTX has been demonstrated. The quantitative analysis of HSO3− in food samples using ZTXvia a smartphone has been also successfully implemented. Simultaneously, the ZTX-based test strips were utilized to quantificationally determine HSO3− in environmental water samples by a smartphone. Consequently, probe ZTX could provide a new method to understand the physiopathological roles of HSO3−, evaluate food safety and monitor environment, and is promising for broad applications.

Novel Application of Metal-Organic Frameworks as Efficient Sorbents for Solid-Phase Extraction of Chemical Warfare Agents and Related Compounds in Water Samples.

In this work, we test metal-organic frameworks (MOFs) as sorbents in the solid-phase extraction (SPE) technique to determine chemical warfare agents (CWAs) and their related compounds in water samples. During this study, we used 13 target compounds to test the selectivity of MOFs thoroughly. Three MOFs were used: MIL-100(Fe), ZIF-8(Zn), and UiO-66(Zr). The obtained materials were characterized using FT-IR/ATR, SEM, and XRD. CWA's and related compounds were analyzed using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The effect of the type of elution solvent and the amount of sorbent (MOFs) in the column on the efficiency of the conducted extraction were verified. The LOD ranged from 0.04 to 7.54 ng mL-1, and the linearity range for the analytes tested extended from 0.11/22.62 (depending on the compound) to 1000 ng mL-1. It was found that MOFs showed the most excellent selectivity to compounds having aromatic rings in their structure or a "spread" spatial structure. The best recoveries were obtained for DPAA, CAP, and malathion. Environmental water samples collected from the Baltic Sea were analyzed using an optimized procedure to verify the developed method's usefulness.

Fluorinated/sulfonated dual-functional three-component covalent organic polymer for adsorption of fluoroquinolones: Preparation, adsorption performance and mechanism

Due to the low performance of traditional water treatment methods, the effective removal of fluoroquinolone (FQs) is of great significance for environmental protection. Based on the structural characteristics of FQs, a fluorinated/sulfonated dual-functional three-component covalent organic polymer [COP, named TpBD-CF3(0.25)SO3H0.75)] was deliberately designed via Schiff reaction, which attempted to realize high removal performance of FQs from different environmental water samples. The results of adsorption performance showed that TpBD-CF3(0.25)SO3H(0.75) could realize high removal performance of FQs via synergistic effect of electrostatic, hydrogen bonding, F-F affinity, π-π and hydrophobic interactions. The adsorbent exhibited fast adsorption rate (can reach adsorption equilibrium in 10 min) and high removal efficiency (> 90 %) for the four concerned FQs, and their adsorption capacity ranged from 65 to 81 mg/g. The results of adsorption kinetics, thermodynamics and isotherm consistently showed that the adsorption of FQs was chemical adsorption. The removal efficiencies of FQs in different water samples were all above 90 % after treated by the adsorbent. The adsorbent has good reusability, and the removal efficiency decreased only by 1 %−4 % after four adsorption–desorption cycles. In addition, the adsorbent has the potential to be used for enrichment of trace FQs in aqueous samples.

Smartphone assisted paper strip-based colorimetric sensing of phosphate and copper ions utilizing bi-ligand intercalated cobalt-MOF as a dual functional nanozyme

Monitoring phosphate and copper ions is vital for environmental and food safety due to associated health risks. To address this need, a new cobalt and bi-organic ligand based metal organic framework (BDC-Co-BIm MOF) has been developed. This MOF acts as a dual-function nanozyme, displaying peroxidase-like activity and selective detection abilities for PO43- ion. The Co(II) nodes and sp2 carbon within the framework exhibit excellent Fenton-like reaction, efficiently catalyzing the conversion of 3,3′,5,5′-tetramethylbenzidine (TMB) into oxidised TMB (oxTMB). Also, steady-state kinetic analysis indicated that BDC-Co-BIm MOF exhibited high affinity toward both TMB and H2O2. The Co(II) nodes and positive charge of the BDC-Co-BIm MOF capture PO43- ion through Co-O-P bonding and electrostatic interaction, limiting the electron transfer between BDC-Co-BIm MOF and H2O2. This reduces TMB oxidation and changes the color from blue to colorless. When ionic Cu2+ ion are added to the system, they react with PO43- ion to form a stable Cu3(PO4)2 complex. This reactivates the electron transfer process, allowing the H2O2 to decompose into •OH. As a result, TMB oxidation is restored and producing the blue color product again. Based on these principles, a colorimetric assay has been developed for the rapid and selective detection of PO43- and Cu2+ ions. A strong linear correlation has been established between their concentrations and the UV absorbance at 652 nm, with limit of detection (LOD) of PO43- and Cu2+ was 0.05 and 0.13 µM, respectively. These limits are notably lower than the thresholds established by the Environmental Protection Agency and World Health Organization (EPA & WHO) at 0.18 µM for PO43- and 30 µM for Cu2+. A Paper-based smartphone-assisted sensing of PO43- and Cu2+ ions was successfully achieved using intelligent Red, Green, and Blue (RGB) analysis. The platform showed high selectivity and performance with environmental water samples. This research presents a novel method for visually detecting PO43- and Cu2+ ions using versatile nanozyme, advancing portable on-site environmental safety analysis.

A highly sensitive and selective electrochemical sensing probe for detection of Edoxaban anticoagulant drug residue in environmental water and drug formulations

ABSTRACT Anticoagulant drugs currently play a crucial role in preventing severe deep vein thrombosis, heart attacks, heart valve diseases and contribute to the regulation of blood flow. Thus, the existing study reports the redox behaviour of Edoxaban (EDX) anticoagulant drug at bare glassy carbon electrode (GCE) for establishing sensitive, and selective adsorptive square wave – cathodic stripping voltammtric (Ads SW-CSV) probe for EDX detection. Under the optimal analytical parameters, the probe displayed good linear dynamic range (LDR) of EDX from 1.0 × 10−6 − 1.0 × 10−5 M. The probe displayed probe sensitivity, limits of detection (LOD) and quantification (LOQ) of 18.5 µA µM−1 cm−2, 3.3 × 10−7 and 1.0 × 10−6 M, respectively. The probe offered quick response, good anti-interference ability towards multiple co-existing species, good recovery (99.21 ± 5.02), reproducibility, and repeatability with relative standard deviation (RSD) of ± 3.0% at 1.0 × 10−6 M of EDX (n = 3). Intraday and interday precisions of the probe were 99.8 ± 1.74 and 99.54 ± 2.08% at 1.0 × 10−6 M of EDX, respectively. The probe was fruitfully applied for EDX detection in its formulations and its residue in water samples with good recovery (99.76 ± 3.768–101.43 ± 0.09) and precision (RSD < 3%) at low and high EDX levels. The tabulated Student t test (t tab =2.78) was higher than the experimental t exp = 1.3–1.7 at 95% probability (n = 5). The probe exhibited good sensitivity and selectivity towards EDX detection in drug formulation and environmental water samples. The probe has long-term stability and high level of anti-interference performance towards EDX detection.

Supramolecular Solvent-Based Liquid–Liquid Microextraction and Preconcentration of Rhodamine B, Methyl Violet, and Eriochrome Black T in Water, Cosmetics, and Food with Spectrophotometric Quantification

Dyes are complex organic compounds that are utilized in many industries. However, excessive exposure to dyes increases susceptibility to various diseases. Their concentrations are below the detection level of many available analytical techniques. Therefore, preconcentration methodology is highly needed prior to their quantification. Herein, a new supramolecular solvent decanol-tetrahydrofuran-based liquid-liquid microextraction method has been established for the first time for the determination of Rhodamine B (Rh B), methyl violet (MV), and Eriochrome black T (EBT) in commercial spices, cosmetics, and water before spectrophotometric quantification. 556, 590, and 530 nm were used for the measurement of Rhodamine B (Rh B), methyl violet (MV), and Eriochrome black T (EBT), respectively. The optimization experiments revealed the best performance at pH 7, 0.9 mL of decanol, 1.3 mL of tetrahydrofuran (THF), and 5 min of vortex time. Under optimized conditions, the limits of detection (LOD) (0.480–0.511 µg L−1), limits of quantification (LOQ) (1.455–1.549 µg L−1), preconcentration factor (PF) (15–20), enhancement factor (EF) (15–20), and relative standard deviation (RSD) (0.5–0.8%) were evaluated. The validation of the method was carried out by standard addition experiments for food, cosmetic, and environmental water samples. The recovery results from 95 ± 6 to 100 ± 4% demonstrate that the method can be successfully applied to practical analysis.

Reusable MOF-Coated Chitosan@Paper Strip Composite for Real-Time Monitoring of Pesticide Pendimethalin and Organoarsenic Feed Additive Roxarsone Levels in Environmental Water, Food, and Vegetable Samples.

An alarming increase in the use of pesticides and organoarsenic compounds and their toxic impacts on the environment have inspired us to develop a selective and highly sensitive sensor for the detection of these pollutants. Herein, a bio-friendly, low-cost Al-based luminescent metal-organic framework (1')-based fluorescent material is demonstrated that helps in sustaining water quality by rapid monitoring and quantification of a long-established pesticide (pendimethalin) and a widely employed organoarsenic feed additive (roxarsone). A pyridine-functionalized porous aluminum-based metal-organic framework (Al-MOF) was solvothermally synthesized. After activation, it was used for fast (<10 s) and selective turn-off detection of roxarsone and pendimethalin over other competitive analytes. This is the first MOF-based recyclable sensor for pendimethalin with a remarkably low limit of detection (LOD, 14.4 nM). Real-time effectiveness in detection of pendimethalin in various vegetable and food extracts was successfully verified. Moreover, the aqueous-phase recyclable detection of roxarsone with an ultralow detection limit (13.1 nM) makes it a potential candidate for real-time application. The detection limits for roxarsone and pendimethalin are lower than the existing luminescent material based sensors. Furthermore, the detection of roxarsone in different environmental water and a wide pH range with a good recovery percentage was demonstrated. In addition, a cheap and bio-friendly 1'@chitosan@paper strip composite was prepared and successfully employed for the hands-on detection of pendimethalin and roxarsone. The turn-off behavior of 1' in the presence of pendimethalin and roxarsone was examined systematically, and plausible mechanistic pathways were proposed with the help of multiple experimental evidences.

A ratiometric fluorescence and colorimetry dual-signal sensing strategy based on o-phenylenediamine and AuNCs for determination of Cu2+ and glyphosate.

A ratiometric fluorescence sensing strategy has been developed for the determination of Cu2+ and glyphosate with high sensitivity and specificity based on OPD (o-phenylenediamine) and glutathione-stabilized gold nanoclusters (GSH-AuNCs). Water-soluble 1.75-nm size GSH-AuNCs with strong red fluorescence and maximum emission wavelength at 682nm were synthesized using GSH as the template. OPD was oxidized by Cu2+, which produced the bright yellow fluorescence oxidation product 2,3-diaminophenazine (DAP) with a maximum fluorescence emission peak at 570nm. When glyphosate existed in the system, the chelation between glyphosate and Cu2+ hindered the formation of DAP and reduced the fluorescence intensity of the system at the wavelength of 570nm. Meanwhile, the fluorescence intensity at the wavelength of 682nm remained basically stable. It exhibited a good linear relationship towards Cu2+ and glyphosate in water in the range 1.0-10 µM and 0.050-3.0µg/mL with a detection limit of 0.547 µM and 0.0028µg/mL, respectively. The method was also used for the semi-quantitative determination of Cu2+ and glyphosate in water by fluorescence color changes visually detected by the naked eyes in the range 1.0-10 µM and 0.30-3.0µg/mL, respectively. The sensing strategy showed higher sensitivity, more obvious color changes, and better disturbance performance, satisfying with the detection demands of Cu2+ and glyphosate in environmental water samples. The study provides a reliable detection strategy in the environment safety fields.

TREMATODE SPECIES DETECTION AND QUANTIFICATION BY ENVIRONMENTAL DNA-qPCR ASSAY IN LAKE CHANY, RUSSIA.

Environmental DNA (eDNA) surveys promise to be a sensitive and powerful tool for the detection of trematodes. This can contribute to the limited studies on trematode ecology, specifically in aquatic ecosystems. Here, we developed species-specific primer and probe sets for Moliniella anceps, Opisthioglyphe ranae, and Plagiorchis multiglandularis cercariae and applied a novel eDNA qPCR assay to detect larval trematodes quantitatively. We evaluated the effectiveness of the assays using filtered lake water samples collected from different sites of Lake Fadikha and Kargat River Estuary in Lake Chany, Russia, showing high species specificity and sensitivity in all 3 assays. Further, all 3 assays had high efficiencies ranging from 94.9 to 105.8%. Moliniella anceps, O. ranae, and P. multiglandularis were detected in the environmental water samples through real-time PCR. Thus, we anticipate that our approach will be beneficial for biomonitoring, measuring, and managing ecological systems.

Dual-colored bacterial biosensor responsive to cadmium, mercury, and lead for detecting heavy metal pollution in seawater

Estimating bioavailable heavy metals in seawater is closely related to the indication of ecological risk. This study combined a CadR-regulated vioABE expression module and a MerR-regulated VioC expression module to generate a novel dual-colored bacterial cell-based biosensor. After genetic optimization, the preferred biosensor could detect as low as 9.7 nM Cd(II), 24.4 nM Pb(II), and 0.5 nM Hg(II). Increased grey-green intensities were observed in Cd(II) (4.9 nM to 40 μM) and Pb(II) (24.4 nM to 200 μM) exposure groups. Interestingly, increased purple intensity was observed in the Hg(II) exposure group (3.7 to 468.8 nM) in a dose-dependent manner. A low-cost and mini-equipment biosensing process was established for detecting pollutant heavy metals in seawater, with the added advantage of providing information on the bioavailability and cytotoxicity of heavy metals. High salinity weakly interferes with the biosensing response to Hg(II). This study shows that novel colorimetric biosensors have the potential to simultaneously report various toxic metals in environmental water samples, contributing to protecting marine ecology.

Thiol-yne click post-synthesis of phenylboronic acid-functionalized magnetic cyclodextrin microporous organic network for selective and efficient extraction of antiepileptic drugs

Owing to their incomplete digestion in the human body and inadequate removal by sewage treatment plants, antiepileptic drugs (AEDs) accumulate in water bodies, potentially affecting the exposed humans and aquatic organisms. Therefore, sensitive and reliable detection methods must be urgently developed for monitoring trace AEDs in environmental water samples. Herein, a novel phenylboronic acid-functionalized magnetic cyclodextrin microporous organic network (Fe3O4@CD-MON-PBA) was designed and synthesized via the thiol-yne click post-modification strategy for selective and efficient magnetic solid-phase extraction (MSPE) of trace AEDs from complex sample matrices through the specific B–N coordination, π-π, hydrogen bonding, electrostatic, and host-guest interactions. Fe3O4@CD-MON-PBA exhibited a large surface area (118.5 m2 g−1), rapid magnetic responsiveness (38.6 emu g−1, 15 s), good stability and reusability (at least 8 times), and abundant binding sites for AEDs. Under optimal extraction conditions, the proposed Fe3O4@CD-MON-PBA-MSPE-HPLC-UV method exhibited a wide linear range (0.5–1000 μg L−1), low limits of detection (0.1–0.5 μg L−1) and quantitation (0.3–2 μg L−1), good anti-interference ability, and large enrichment factors (92.2–104.3 to 92.3–98.0) for four typical AEDs. This work confirmed the feasibility of the thiol-yne click post-synthesis strategy for constructing novel and efficient multifunctional magnetic CD-MONs for sample pretreatment and elucidated the significance of B–N coordination between PBA and N-containing AEDs.

Pyrene‐based ratiometric fluorescent chemosensor for sensitive detection of hypochlorite in a perfect aqueous solution

AbstractWe synthesized a pyrene‐based sensitive fluorescent chemosensor, TPA‐Cl ((E)‐N,N,N‐trimethyl‐2‐oxo‐2‐(2‐(pyren‐1‐ylmethylene)hydrazinyl)ethan‐1‐aminium chloride), to detect hypochlorite in a perfect aqueous solution. TPA‐Cl showed high selectivity for hypochlorite through fluorescence color change from sky blue to blue. The detection limit for hypochlorite was calculated as 0.27 μM, which is a quite low value. Moreover, the presence of other anions or ROS hardly hindered the sensing of hypochlorite by TPA‐Cl. Furthermore, TPA‐Cl could be applied successfully as a test kit for the simple recognition of hypochlorite. Surprisingly, TPA‐Cl is the first pyrene‐based fluorescent chemosensor that can detect ClO− by using the TPA‐Cl‐coated test kit. Moreover, TPA‐Cl could achieve the quantification of ClO− in various environmental water samples. The hydrolytic cleavage and oxidation mechanism of TPA‐Cl by hypochlorite was elucidated through UV–vis and fluorescent spectroscopy, 1H NMR titration, ESI‐MS analysis and DFT calculation.

A biomass composite based on natural deep eutectic solvent and magnetic chitosan for the solid phase extraction of PPCPs

Water pollution has always been a concern. The synergistic function of deep eutectic solvents (DESs) and adsorbent materials has aroused continuous attention, especially in terms of water pollution. In this study, four natural DESs were synthesized from choline chloride ([ChCl]) with glucose ([Glu]), fructose ([Fru]), sucrose ([Suc]) and maltose ([Mal]), respectively. The DESs were then coated onto the surface of magnetic chitosan (MCS) to form DESs-MCS composites. The structures of the DESs-MCS were confirmed by XRD, FT-IR, VSM, TGA and TEM. Afterwards, the DESs-MCS was combined with solid phase extraction (SPE) to separate PPCPs (production and extensive application of pharmaceuticals and personal care products) including diclofenac sodium salt (DCF) and tetracycline (TC). [ChCl][Fru]-MCS was selected as a representative adsorbent to extract DCF, and some influencing factors such as the mass of the [ChCl][Fru]-MCS, the volume of the DCF solution and the type of the desorption solvent were systematically investigated. Moreover, the adsorption of DCF was well conformed to the Langmuir adsorption isotherm and the Pseudo-Second-Order kinetic model. The maximum adsorption capacity of [ChCl][Fru]-MCS on DCF was up to 180.2 mg∙g−1. Furthermore, the relationship between solution pH and adsorption capacity, combined with XPS and FT-IR analysis of the [ChCl][Fru]-MCS before and after adsorption, were explored to get insight into the adsorption mechanism. It turned out that the electrostatic interactions play a vital role in the extraction process, and the hydrogen bonding was also considered as the main driving force based on the types of the functional groups of DES (such as –OH, –NH2). At last, the practical applicability of the [ChCl][Fru]-MCS was evaluated by performing the regeneration experiments and analyzing the real sample. The results demonstrated that the [ChCl][Fru]-MCS could be recycled six times without significant loss of adsorption capacity and the [ChCl][Fru]-MCS could be successfully applied to extract DCF from environmental water samples. The limit of detection and limit of quantification obtained for DCF were 0.27 and 0.90 μg∙mL−1, respectively. The RSDs of the precision and repeatability experiments were 0.71 % and 0.35 %, respectively. Hence, the prepared DES-MCS proved to be a potential adsorbent in the field of wastewater.

Discrimination and simultaneous quantification of poly(ethylene terephthalate) and poly(butylene terephthalate) microplastics in environmental samples via gas chromatography-tandem mass spectrometry.

A method has been developed to quantify PET and PBT microplastics (MPs) based on depolymerization and detection of depolymerization products by gas chromatography-tandem mass spectrometry (GC-MS/MS) without a complex separation process from environmental samples. Under the optimal depolymerization conditions, PET and PBT were efficiently convertedto ethylene glycol (78%) and 1,4-butanediol (87%), respectively. Subsequently, the linear curves were constructed between signal intensities of depolymerization products and polymer masses by GC-MS/MS, and the correlation coefficients of PET and PBT were 0.996 and 0.997, respectively. The spiking and recovery experiments of PET and PBT in the environmental samples showed that the recovery was stable in the range 89-100%, and the limit of detection was 4.95μg and 1.39μg of PET and PBT, respectively. The method has been proven to be capable of simultaneous identification and quantification of PBT and PET MPs in real environmental water samples without complex separation process, which provided a scheme for the determination of microplastics.

A water-soluble red-emitting fluorescence probe for detecting hazardous hydrazine in environmental waters and biosystems

Hydrazine (N2H4), a crucial chemical raw material, enhances people's lives and fosters human progress. Hydrazine usage or leakage has caused environmental contamination, affecting water, soil, and living beings. Hydrazine simultaneously presents a possible risk to human health due to its carcinogenic properties. Thus, quick and precise detection of hydrazine is crucial in environmental studies and biological contexts. We prepared a red-emitting fluorescence turn-on probe (XT-HZ) to detect hydrazine specifically. The probe has a low detecting limit for hydrazine (63 nM) with excitation wavelength at 570 nm and emission wavelength at 625 nm. Besides, the probe XT-HZ had excellent water solubility, high selectivity, and good sensitivity for detecting hydrazine. Finally, probe XT-HZ was applied in the imaging of N2H4 in living cells, zebrafish and environmental water samples.

The Role of Automation in the Analysis of Manganese in Environmental Water Samples

Manganese is considered an emerging pollutant and it is perceived as a potential threat to human health and aquatic ecosystems. The need to determine and monitor the presence of Mn in environmental water requires increasingly precise and accurate chemical analytical techniques that provide reliable information to take timely measures in the event of potential environmental contingencies. The automation by flow analysis technique has allowed analytical procedures to isolate and preconcentrate manganese in environmental water samples. Additionally, it brings forth benefits such as greatly enhancing the sample processing capacity and a reduced time and reagent usage, leading to cost savings and minimized waste production, thereby aligning with the principles of green chemistry. In this review, a recent report of some flow analysis techniques (FIA, rFIA, SIA, MSFIA, LOV, and MPFS) is presented, highlighting the trend of automation, whose portability and miniaturization allow for complete in situ analysis. There are two remarkable analytical features from the studies evaluated here, which are sample throughput and accuracy, with a maximum processing time of 120 samples h−1 and an accuracy of 98%. The implementation of flow analysis techniques offers several advantages, such as miniaturization and portability. The discussed methodologies achieved limits of quantification as low as 0.26 µg L−1, enabling environmental monitoring that can easily detect the reference value of 0.05 mg L−1, established by the WHO and the EPA.

Green synthesis of MIL53(Al)-modified paper-based analytical device for efficient extraction of neonicotinoid insecticides from environmental water samples

BackgroundThere is a need to develop low-cost, reliable and portable devices to enhance the efficiency of microextraction techniques in complex samples. Metal-organic frameworks (MOFs) have proven to be promising sorbents due to their well-documented properties. However, their green preparation and combination with paper-based substrates have not been satisfactorily explored to fabricate sustainable sorptive phases. ResultsIn this work, the hybridization of a paper substrate (as a sustainable support) with MOFs (as a sorptive phase) was carried out by one-pot approach. Concretely, the selected MOF, MIL-53(Al), was in-situ growth onto the paper surface in aqueous solution without the need for high temperature or pressure, thereby aligning with the Green Analytical Chemistry principles. The optimized composite (MIL-53(Al)@cellulose paper) was characterized and evaluated as extraction sorbent for five neonicotinoids (NEOs) (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid). Furthermore, its feasibility was demonstrated by isolating these pollutants from environmental water samples, followed their determination by HPLC coupled to diode array detection. The whole method showed satisfactory analytical performance with recoveries between 86 and 114 %, suitable precision (with RSD lower than 14 %), and limits of detection ranged from 1.0 to 1.6 μg L−1. Besides, the greenness of the method was assessed by application of different existing metrics. The developed extraction device was affordable (<0.08 €/device) and mechanical and chemically stable, being possible its reuse more than 11 cycles, thus demonstrating its suitability for rapid screening of pesticides in environmental samples. SignificanceThis report presents, for the first time, the green synthesis of MIL-53(Al)cellulose paper composite and its application as a sorptive phase for the extraction of NEOs from environmental water samples. We believe that the proposed strategy for fabricating these sustainable paper-based sorptive phases paves the way for further hybridizations with other MOFs or materials. Additionally, it opens up large possibilities for their application in extraction of pollutants or other hazardous compounds in aquatic environments.