Trends in Environmental Analytical Chemistry最新文献

Molecularly imprinted polymers (MIPs), prepared by the interaction forces such as forming covalent or non-covalent bonds by crosslinkers and initiators, are new types of specific recognition polymers with particular cavities. This is an ideal class of materials for wastewater treatment because of the particular holes left by the elution process. This review discusses the development process, classification, synthesis principles, systems, and polymerization methods of MIPs. At the same time, the adsorption mechanism of Copper (Cu), Mercury (Hg), Chromium (Cr), Silver (Ag), and Lead (Pb) in the MIPs technique are studied. Finally, some suggestions and prospects for the future development of MIPs are also put forward.

Although glyphosate (Gly) is one of the most widely used agrochemicals, it is also of the most difficult to measure. Gly, its metabolites, and related compounds cannot be sought within the scope of multi-residue methods. Specific so-called single-residue methods are used instead. Liquid chromatography-mass spectrometry (LC-MS) is currently the most widely used technique for determining Gly and its metabolites. This review addresses the different LC-MS-based methods proposed for the determination of Gly and related species in food and environment matrices. Sample preparation (food and environment), as well as their determination based in novel liquid chromatography/mass spectrometry approaches including different specific stationary phases are presented and the specific analytical challenges, strengths and drawbacks are critically discussed.

It is known that environmental pollution, which is the result of human-induced industrial, domestic, and agricultural practices, poses a threat to our planet. The increasing human population caused several problems such as water and air pollution, which have reached levels threatening human health. There are many different hazardous chemical and biological environmental pollutants in soil, air, and wastewater. It is extremely important to evaluate these health risks and detect these pollutants. The use of electrochemical methods for the detection of environmental pollutants comes to the forefront recently with advantages such as sensitivity, fast response, low cost, and practical use by miniaturization. The molecular imprinting technique is a popular method used for substance analysis by creating a cavity specific to the substance to be analyzed with the polymer used. The use of molecularly imprinted polymer in electrochemical methods and its modification with various nanomaterials bring advantages such as high selectivity, robustness, and sensitivity to electrochemical sensors. Here, the sensitive determination of environmental pollutants with different nanomaterial-modified molecularly imprinted polymer-based electrochemical sensors, the use of different polymerization techniques, and nano-sized modification agents in sensors are evaluated by reviewing recent studies in the literature.

Ions play a pivotal role in the biological regulatory processes and catalyzing enzymatic reactions; however, increased levels in the human body leads to many health risks or toxicity. To circumvent this, periodic and precise monitoring of significant ions in environmental, biological, chemical, and food samples are necessary, which need to be mapped/monitored continuously. This has prompted researchers to develop cost-effective, handy, and rapid techniques which can be fruitful for even untrained personnel by obviating manual user instructions, lengthy sample preparation steps, and costly instruments. The exploitation of user-friendly behavior, affordable price, and ubiquitous usage of smartphones has led to the development of a plethora of smartphone-based methodologies whereby they can serve as devices, detectors, or interfaces. Their in-built high-resolution rear camera, ambient light sensors, wireless connectivity, internal storage, and global positioning systems minimize the cost and simplify the fabrication of developing point-of-care testing devices, making them operable in challenging conditions with limited resources. Coupling smartphones with iCloud technology allows the synchronous storing and online transmitting of databases to consumers even in remote areas, which helps in real-time monitoring and continuously scrutinizing contaminants in the environment. This is not an exhaustive review but enumerates the progress made in the development of smartphone-based analytical aids by incorporating advanced device fabrication strategies and hassle-free analytical protocols during the past years (2014–2021). An account of key features like sensing performance of the developed methods in terms of selectivity, sensitivity, and detection limits and their limitations for recognition of environmental and biologically eminent ions is also discussed. Lastly, this review paves the way for the development of advanced innovative analytical techniques employing smartphone technology for the foreseeable future to ensure point-of-care human safety.

The development of greener and more efficient materials for extracting environmental contaminants from various matrices is a growing area of research. Materials that do not cause secondary pollution are highly desirable in such applications. Chitosan (CS) is a non-toxic biopolymer enriched with amino and hydroxyl groups, used not only for extracting pollutants but also for crosslinking and functionalizing CS with other materials. The composites of CS with carbon, metal-organic frameworks, metal and metal oxide nanoparticles, and magnetic materials have been used to extract various inorganic and organic analytes in aqueous samples. CS-based sorbents have been evaluated across multiple extraction techniques, such as dispersive solid phase extraction, magnetic solid phase extraction, solid phase microextraction, syringe solid phase extraction, membrane-protected solid phase extraction, and others. This review offers an overview of the CS-based sorbents in analytical extractions, highlighting their strengths, weaknesses, and potential solutions. At the end, a brief overview of the CS-based adsorbents in water treatment applications is also provided.

Large amounts of flowback and produced water (FPW) have been generated from hydraulic fracturing process for the production of unconventional gas such as shale gas. Complex organic pollutants are abundantly present in FPW with revealed toxicity to aquatic organisms and these contaminants may transfer into surrounding aquatic environment. Characterization and determination of complicated organic pollutants in FPW remains a challenge due to its complex composition and high salinity matrix. This review article covers the progress of recent 5 years regarding the sample preparation and instrumental analysis methods and thus summarizes the advantages and disadvantages of these methods for critical analysis of organic contaminants in FPW samples. Furthermore, the natural distribution of detected organic compounds and their transformation were reviewed and discussed to enhance the understanding of spatial and temporal behaviors of these organic pollutants in natural environment, paving the way for future development of pollution control policies and strategies. Enlightened by the studies of FPW contamination in the US, the investigations of FPW contamination in China continued to grow due to rapidly growing production of shale gas in China and resulted pollution.

Microplastics (MPs) have attracted wide attention all over the world as a remarkable pollutant. While MPs are spreading throughout several complex environmental matrices, various experiments till date have been preliminary concentrate on aquatic ecosystems. Terrestrial sources namely solid waste-origin have remains unexplored, although they contribute largely for aquatic microplastics origin. Simultaneously, terrestrial systems under human activity, like healthcare units, are likely to be polluted by various plastic ingredients. Solid waste MPs sources primarily include sanitary landfilling, food waste, wastewater treatment end-product (sludge), tire wear, textile washing and paint failure. These microplastics caused adverse impacts on ecosystem, environment, and health. Accordingly, the present study addressed solid waste MPs’ occurrence and sources, identification, quantification, characterization, fate, and degradation pathways for developing comprehensive management strategies following the principles of circular economy. In particularly, this paper critically demonstrated solid waste MPs sources, solid waste MPs sampling followed by identification and quantification by adopting combined chemical (e.g., spectroscopy viz., Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy), physical (e.g., microscopy such as transmission or scanning electronic microscopy, TEM or SEM) and thermal analyses. Additionally, the strengths and limitations of each analytical technique are discussed critically with practical aspect. Further, the MPs related national and international regulations or laws and their subsequent relevance to solid waste MPs management with future challenges are discussed very critically. Finally, the outcomes of the review paper will be valuable to different stakeholders for effective policy implementation.

The collection, storage, and transportation of water samples from far-off places to the labs is a pretty challenging task. It can cause contamination, degradation, or losses of the analytes, leading to errors in the analysis. On-site sample preparation provides an opportunity to extract the analytes into suitable extraction media that preserves the analytes and is easy to handle in terms of storage and transportation. However, the required equipment for on-site sample preparation should be simple, portable, and energy-efficient. Solvent- and sorbent-based microextraction approaches and the modern variants of solid-phase extraction have shown great potential for on-site sample preparation because of reduced consumption of solvents and low energy requirement. This review provides an overview of the application of different extraction techniques in on-site sample preparation, their advantages, and their limitations. The recent advances combining on-site extraction and analysis have also been critically discussed.

Formation of aqueous secondary organic aerosol (aqSOA) at the air – liquid interface recently has attracted a lot of attention in atmospheric chemistry. The discrepancies in mass distributions, aerosol oxidative capacity, liquid water content, hygroscopic growth of aerosols, and formation of clouds and fogs suggest that interfacial chemistry play a more important role than previously deemed. However, detailed mechanisms at the air–water interface remain unclear owing to the lack of comprehensive understanding that underpins complicated interfacial phenomena, which are not easily measurable from field campaigns, laboratory measurements, or computational simulations. This review highlights relevant and recent technical advancement employed to study aqSOA encompassing spectroscopy and mass spectrometry. The current knowledge on the aqSOA processes is digested with an emphasis on recent research of interfacial aqSOA formation including laboratory studies and model simulations. Finally, future directions of the interfacial chemistry are recommended for field and laboratory studies as well as theoretical efforts to resolve interfacial challenges in atmospheric chemistry.

The discharge of heavy metal ions into water resources as a result of human activities has become a global issue. Contamination with heavy metal ions poses a major threat to the environment and human health. Therefore, there is a dire need to probe the presence of heavy metal ions in a more selective, facile, quick, cost-effective and sensitive way. Conventional sensors are being utilized to sense heavy metal ions; however, various challenges and limitations like interference, overlapping of oxidation potential, selectivity and sensitivity are associated with them that limit their in-field applicability. Hence, nanomaterial based chemical sensors have emerged as an alternative substitute and are extensively employed for the detection of heavy metal ions as a potent analytical tool. The incorporation of nanomaterials in sensors increases their sensitivity, selectivity, portability, on-site detection capability and device performance. Nanomaterial based electrodes exhibit enhanced performance because surface of electrode at nano-scale level offers high catalytic potential, large active surface area and high conductivity. Therefore, this review addresses the recent progress on chemical sensors based on different nanomaterials such as carbon nanotubes (CNTs), metal nanoparticles, graphene, carbon quantum dots and nanocomposites for sensing heavy metals ions using different sensing approaches. Furthermore, various types of optical sensors such as fluorescence, luminescence and colorimetry sensors have been presented in detail.