•The miniaturization of HPLC, thought c-LC and n-LC provide green methodologies.•The LC sample treatment can be performed on-line and off-line.•IT- SPME minimize sample treatment and allows to inject ...the sample directly.•Most of environmental contaminants found are non-regulated compounds.
The greater and more widespread use of chemicals, either from industry or daily use, is leading to an increase in the discharge of these substances into the environment. Some of these are known to be hazardous to humans and the environment and are regulated, but there is a large and increasing number of substances which pose a potential risk even at low concentration and are not controlled. In this context, new techniques and methodologies are being developed to deal with this concern. Miniaturized liquid chromatography (LC) emerges as a greener and more sensitive alternative to conventional LC. Furthermore, advances in instrument miniaturization have made possible the development of portable LC instrumentation which may become a promising tool for in-situ monitoring. This work reviews the environmental applications of miniaturized LC over the last 15 years and discusses the different instrumentation, including off- and on-line pretreatment techniques, chromatographic conditions, and contributions to the environmental knowledge.
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•The simple, fast and highly sensitive method for the determination of pinoxaden is based on fluorescence measurement of the Fe(III) based coordination complex of pinoxaden in the ...basic medium at 337 nm.•The signaling product is kinetically stable at room temperature having maximum fluorescence intensity with 0.2 µg mL−1 of Fe(III) at pH 9.•The complex shows a linear concentration range from 1 × 10−4,-1 × 10−3 µg mL−1 with a coefficient of determination R2 = 0.9917.•Density functional theory simulations shows stronger interaction energy (-1.11 eV) of Fe(III) ion with the pinoxaden.•The proposed approach is applied to quantify pinoxaden in the formulation and real agricultural and environmental samples and shows excellent recovery.
Keeping in view the toxicity of pesticides, development of analytical methods for their determination in environmental samples is the need of the day. Herein, a simple, fast and sensitive method for the determination of pinoxaden has been described. The kinetically stable, Fe(III) based complex of pinoxaden was formed at room temperature showing maximum fluorescence intensity at 337 nm with 0.2 µg mL−1 of Fe(III) at pH 9. The complex shows a linear response in the concentration range of 1 × 10−4-1 × 10−3 µg mL−1 with a coefficient of determination R2 = 0.9917, limit of detection and limit of quantification of 8.1 × 10−5 and 2.4 × 10−4 µg mL−1, respectively, and relative standard deviation and maximum matrix effect of 0.021% and 2.13%. Density functional theory simulations were used to understand the nature of Fe(III) based complex of pinoxaden. The larger negative interaction energy of −1.11 eV evince that the Fe(III) strongly coordinated with the N-atom shared by oxadiazopine ring and the pyrazole ring and the O atom of –CO group of side chain, which are consistent with the experimental results. Interference study shows that among the metal ions studied, only Cu(II), Co(II) and Pb(II) show reasonable interference effect. The proposed approach was applied to quantify pinoxaden in the formulation and real agricultural and environmental samples. The results indicate excellent recovery in the range of 89.44 ± 1.38–97.51 ± 2.62 % for wheat, barley, water and soil samples. In soil samples no residue was quantified while in the wheat and barley samples the residue found was below the maximum residue limit. Under optimized experimental conditions, the proposed method was found to be simple, fast, reasonably interference free and has trace level sensitivity. The method was found to be comparable and even superior to some literature methods for determination of pinoxaden in complex matrices.
This study evaluated sample processing methods and the presence of organic matter on detection of porcine epidemic diarrhea virus (PEDV) from environmental samples using real-time reverse ...transcriptase-polymerase chain reaction (qRT-PCR). Steel coupons were inoculated with PEDV and different types of organic material contamination. Surface samples were collected and processed in one of four ways: none, centrifugation, syringe filtration, or combination of centrifugation and syringe filtration, then submitted for PEDV qRT-PCR. There was a surface inoculation type by processing method interaction (P < .001) that impacted the sample cycle threshold value. Centrifugation resulted in the most consistent detection of PEDV RNA.
•This part focuses on a)the advantages and disadvantages of solid-phase extraction (SPE) versus liquid–liquid extraction (LLE) andb)the controversies and contradictions found in the literature in ...i.the selection of sorbents andii.the optimization of conditioning and elution protocols and recoveries by SPE.•Moreover, the study reveals the lack of selectivity of most sorbents and SPE protocols.•We concluded that SPE procedures are yet to be systematized in the future.
Solid-phase extraction (SPE) is the most widely used method for the extraction, changing of solvents, clean-up, concentration and fractionation of organic compounds from several samples.
Here, we attempt to resolve the debates surrounding the suitability of sorbents for the extraction of several compounds, conditioning, washing and elution protocols, as well as the recoveries achieved by each SPE protocol. The lack of systematization and homogenization limits the efficient implementation of reliable SPE procedures.
This part focuses on the advantages and disadvantages of SPE versus liquid–liquid extraction (LLE), controversies and contradictions found in the literature with respect to the selection of sorbents, optimization of conditioning and elution protocols and recoveries by SPE. Moreover, it reveals the lack of selectivity of most sorbents and SPE protocols. It is divided into the following sections: applications of SPE, fractionation by SPE, outlook and conclusions.
The growing co-contamination of multiple metal ions seriously influences human health due to their synergistic and additive toxicological effects, whereas the rapid discrimination of multiple heavy ...metal ions in complex aquatic systems remains a major challenge. Herein, a high- throughput fluorescence sensor array was fabricated based on three gold nanoclusters (GSH-Au NCs, OVA-Au NCs, and BSA-Au NCs) for the direct identification and quantification of seven heavy metal ions (Pb2+, Fe3+, Cu2+, Co2+, Ag+, Hg2+ and As3+) from environmental waters without sample pretreatment other than filtration. At the detection system, three gold nanoclusters with various ligands possessed distinct binding capacities against metal ions and induced aggregation-induced fluorescence enhancement and quenching, resulting in a unique pattern of fluorescence variations. Meanwhile, integrated the collected fluorescence fingerprints with linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA), a discrete database was obtained for the accurate recognition and sensitive detection of metal ions. Under the optimized conditions, the limit of detection (LOD) of the proposed fluorescence sensor array for metal ions detection at nM concentration level along with a satisfactory accuracy. Importantly, our study indicated that the fluorescence sensor array could be widely used as a general platform in environmental monitoring against multiple targets at low concentrations.
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•A fluorescence array sensor based on three gold nanoclusters was developed.•The array sensor could realize the identification of seven heavy metal ions.•A discrete database was constructed by integrating collected fluorescence fingerprints.•The proposed array achieved acceptable feasibility in real water samples detection.
Solid-phase extraction (SPE) is the most widely used method for the extraction, changing of solvents, cleanup, concentration, and fractionation of organic compounds from a number of samples. This ...procedure is also very useful for desalting proteins and sugar samples. However, most SPE procedures are still poorly developed, with little consideration to the physics involved in the process and are described as largely empirical, labor-intensive, and time-consuming trial-and-error processes, without much systematization.
The objective of this study is to propose a number of contradictions, disagreements, failings, and shortcomings of the SPE procedures found elsewhere. The different arguments introduced in this study attempt to challenge the suitability of this procedure, particularly when it is conducted in the traditional manner (under gravity and at a high flow rate).
The first part of this study focuses on describing the state-of-the-art in SPE and its physical fundamentals.
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•A novel method for biosynthesized silver nanoparticles based on bitter orange bloom extract was presented.•AgNPs was subsequently utilized to detect and determine cyanide ions.•The ...developed colorimetric sensor can detect cyanide ions with good selectivity in aqueous solutions.
Developing new methods for detecting and determining toxic anions is an essential parameter from waste sources for industrial and environmental scientists. This study presented, a new process for the biosynthesis of silver nanoparticles (AgNPs) based on the bitter orange bloom extract and its potential as a highly selective and sensitive chemosensor for detecting and quantifying cyanide ions. These biosynthesized AgNPs have a sharp and intense surface plasmon resonance (SPR) peak around 405 nm. AgNPs with a yellow color can be changed to colorless in the presence of a certain concentration of cyanide ions due to forming a new adduct between AgNPs and cyanide ions. Hence, the SPR intensity of AgNPs decreases, and the color of the solution becomes colorless. The sensor response to cyanide ions was linear in the concentration range of 49.7 to 1208.8 nM, and the detection limit was equal to 7.9 nM. As an applicable alternative, this assay is highly capable of qualitative and quantitative measurements of cyanide ions in the waste and toxic samples.
In recent years, the usage of magnetic sorbents in sample preparation and contaminants removal techniques has received considerable attention as they can be easily recovered using an external ...magnetic field. This ability reduces sample treatment time and simplifies the procedure. In this review, the most recent and outstanding applications (2017–2021) of magnetic sorbents for preconcentration and removal purposes is reviewed and discussed. This review firstly, discusses preparation, advantages, limitations and possible interactions of different types of magnetic sorbents briefly (nanoparticles, nanocomposites, sponges, foams, beads and hydrogels) and also views on how to choose the appropriate sorbent based on the intended application. Secondly, the role of magnetic sorbents in the common sample preparation techniques such as solid phase extraction, solid phase microextraction, stir bar sorptive extraction and liquid phase microextraction are also investigated and discussed. In conclusion, remarkable features and future trends are commented.
•Different types of magnetic sorbents were described.•Synthesis, distinct features and possible interactions of magnetic sorbents were discussed.•The role of the magnetic sorbents in improving samples preparation techniques was discussed.•Recent applications of magnetic sorbents in separation techniques were discussed.•Attractive trends in the field of magnetic sorbents were highlighted.
Cyclosporiasis is an emerging disease that is ubiquitous in humans and other animals worldwide. Cyclospora cayetanensis , which is distributed in the tropical and subtropical regions, and endemic in ...several developing countries, is the only species of Cyclospora resulting in cyclosporiasis in humans. The main objective of this review was to summarize the prevalence of Cyclospora in humans, animals, and environmental samples in Nepal. The overall prevalence of Cyclospora in humans has been reported to be 10.3% (3,785/36,570), including 3.6% (60/1,640) among HIV immunocompromised cases, 2.1% (210/9,733) among children, and 13.9% (3,515/25,197) in humans of all age categories, while the prevalence was calculated to be 2.9% (29/983) and 10.5% (9/85) in domestic and wild animals, respectively. The molecular characterization data on Cyclospora as related to Nepal is limited to a very few positive isolates from humans, dogs, chickens, and monkeys. Exposure to sewage water and contaminated fresh food items, and the presence of domestic animals appear to have been associated to an outbreak of Cyclospora in humans. Considering Cyclospora spp. as the etiologic agent for diarrhoea, a comprehensive, wider scale molecular epidemiologic study in humans, animals, and environmental samples is warranted to elucidate the exact distribution loci and probable outbreak of cyclosporiasis in Nepal.
Metal nanoparticles have garnered a significant interest in various fields of science because of their remarkable optical properties, and they have shown a great impact in improving the sensitivity ...of UV–Visible spectrometry, just like as expensive analytical instruments. Modifications of metal nanoparticles (Au, Ag and Cu) with specific ligands have shown great potentiality to establish miniaturized colorimetric assay of wide variety molecules, offering the quantification of trace level target analytes via the color changes, which could be noticed with naked-eye. The interface between the ligand chemistry of metal nanoparticles and trace level pesticides leads to the specific covalent and non-covalent interactions, thereby causing a significant color change in the metal nanoparticles via the aggregation of metal nanoparticles induced by pesticides. In this review, the role of ligand chemistry on the surfaces of metal nanoparticles (Au, Ag and Cu) for colorimetric detection of various pesticides is summarized. This review briefly illustrates the aggregation mechanisms involving in the colorimetric detection of pesticides using functionalized metal nanoparticles as colorimetric sensors. Further, this review also summarizes the used ligands on the surfaces of metal nanoparticles (Au, Ag and Cu) for visual readouts of various pesticides at minimal volumes of samples. Finally, we outline the challenges and future perspectives of ligand chemistry on metal nanoparticles for colorimetric assays of pesticides from various samples.
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•Ligand chemistry plays key role in tuning the sensing applications of metal NPs.•Functionalized Au NPs acted as sensors for colorimetric assaying of various pesticides.•Assay of pesticides was based on the changes in SPR band and color of metal NPs.•Metal NPs-based colorimetric sensors exhibited lower detection limits.•Pesticides were sensitively detected even at ultra-trace levels (nM to pM).
