Trends in Environmental Analytical Chemistry最新文献

Metabolomics is a discipline aiming to characterize the presence of metabolites in biological matrices under specific conditions. In recent years, metabolomics has increasingly been used in environmental research to explore the metabolic changes in humans and organisms under diverse environmental exposures, mainly chemical pollutants. Hence, metabolomics has become a key tool in exposome studies, to explore the biological effects at molecular level exerted by xenobiotics. To understand the biological mechanisms triggered by specific chemical compounds, the combination of metabolomics with information about the presence of xenobiotics in the biological samples (xenometabolome), and other molecular information obtained from omics technologies (e.g. transcriptomics, proteomics) is crucial, both in exposome studies, and adverse outcome pathways (AOPs) development.

This review aims to describe the main applications of metabolomics in the assessment of biological effects induced by chemical pollutants on ecosystems and human health, both in exposome studies and in laboratory-controlled assays. Different analytical aspects and recent analytical challenges are presented and discussed. Finally, the different opportunities and the current situation of metabolomics as a tool in chemical safety assessment for regulatory applications are reviewed.

This review provides a comprehensive evaluation of solidified floating organic drop microextraction (SFODME) procedures for metal ions preconcentration and their contributions to green chemistry. In this article we focused on the modifications that have been performed in the recent years to improve this environmentally friendly procedure. Among the most important of these modifications are the inclusion of ultrasonic energy, vortex and air agitation to enhance the dispersion process. The article also discussed new challenges in the procedure by using more ecofriendly solvents as extractants such as ionic liquids, deep eutectic. and supramolecular solvents. The coupling of SFODME with solid phase extraction increases selectivity and efficiency of the preconcentration procedure.

This review includes one hundred and two peer reviewed papers that focus on metabolic residues of the two most used licit drugs globally, nicotine (nicotine, cotinine, trans-3’-hydroxycotinine – HCOT) and alcohol (ethyl sulphate and ethyl glucuronide), in waste- and environmental waters. Sampling strategies and analytical methods are also summarised and discussed. Although grab sampling is the most widely applied method for collecting environmental samples (74% cases), wastewater samples are typically composite samples collected automatically at the wastewater treatment plants (66% cases). Sample preparation and analysis usually include solid-phase extraction (SPE) followed by reverse-phased liquid chromatography with tandem mass spectrometry detection (RP-LC-MS/MS) for nicotine residues. In contrast, alcohol residues are commonly determined via direct injection onto the LC-MS/MS using an ion-pair reagent to improve retention, leaving room for method improvement, e.g., introducing a suitable extraction procedure to achieve lower detection limits and quantification. In comparison to alcohol residues, more studies look into nicotine residues (85% of the studies). Concentration ranges for nicotine, cotinine, HCOT and ethyl sulphate were < 424,000, < 42,300, 50–52,000 and 500–33,000 ng/L in wastewater influents and 15–32,000, < 18,000, 15–1,552 and < 500 ng/L in effluents, while nicotine (12.6–947 ng/L) and cotinine (17–62 ng/L) were detected in reclaimed waters. Among environmental waters, the highest concentrations of nicotine residues were measured in surface waters (nicotine: < 9,340 ng/L, cotinine: < 6,582 ng/L and HCOT: 14–777 ng/L), while their concentrations in groundwater and drinking water were generally in the low ng/L range. This review also reveals the discrepancy between the number of studies in developed countries (90%) compared to developing countries and the need for more studies in the former, where most wastewater flows untreated into the environment.

Pesticides are substances or mixtures used to prevent, control, and reduce harmful organisms, are divided into various groups as carbamates, organophosphates, organochlorines, pyrethroids, fungicides, herbicides, and rodenticides. Uncontrolled and long-term use of pesticides has become an important issue that causes environmental pollution and health problems. Therefore, it is necessary to develop effective sensors to determine pesticides in various samples. Electrochemical techniques stand out with high sensitivity, easy application, low cost, and user-friendliness, among other analysis techniques such as spectroscopic and chromatographic methods. Furthermore, carbon nanomaterials are advantageous materials for the sensor design as modification agents due to their unique electrical, physical, electrocatalytic, and chemical features. In this review, the most significant studies on the electroanalysis of pesticides (e.g., carbaryl, carbofuran, chlorpyrifos, malathion, methyl parathion, paraoxon) using carbon-based nanosensors in the last five years are overviewed. In addition, electrochemical methods and the carbon nanomaterials used in these studies are also evaluated.

Protected Areas (PAs) are locations for conservation, internationally recognized for their natural, ecological, and/or cultural values. Human presence in PAs is generally limited to minimal or banned exploitation of natural resources. However, different threats to PAs are evident as a result of short and long-range transport of organic pollutants of legacy and emerging concern. There has been a shift of interest in legacy pollutants such as persistent organic pollutants (POPs) to emerging compounds, resulting in a need for improved monitoring strategies in PAs. Here, we highlight the main advances in environmental analytical chemistry for legacy and emerging pollution monitoring in PAs. Trends in sampling, sample preparation and instrumental determination of multiclass organic pollutants in biotic and abiotic matrices are presented and discussed. Here, we considered the most relevant and recent literature regarding organic pollutants in PAs from terrestrial to aquatic landscapes collected within 2015 to the present time frame.

Over the last several years, a number of studies have concentrated on the occurrence, potential sources, and ecological implications of soil systems. However, the studies’ methodological aspects have received little attention. Thus, this study performed a quality assessment for the methodological aspects of soil microplastics studies by adopting the Criteria for Reporting and Evaluating Ecotoxicity Data (CRED) evaluation method. A total of 35 soil microplastic studies have been evaluated in terms of methodological aspects using 13 criteria, namely, sampling methods and strategy, sample processing and storage, sample size, laboratory preparation, clean air conditions, chemical purity, negative control, positive control, sample pre-treatment, microplastics particle data, particle size, particle shape and polymer type identification. The quality assessment findings indicated that no study scored a maximum of two in all criteria, reiterating the urgent need for enhanced quality assurance for future soil microplastics studies. The average quality assessment scores in soil microplastics studies also indicated that the conditions requiring the most improvement involve both the criteria of positive controls and the criteria of clean air conditions. With a value of zero in 13 assessed criterion, the relevance of the study’s findings in environmental risk assessment was restricted, suggesting that future studies should consider strengthening the implementation and reporting of QA/QC protocol. Adoption of proper quality assurance and contamination control measures will guarantee high data quality and establish confidence in the study’s findings, which allow for reproducibility and comparability as well as acceptability to be utilized in risk assessments.

Nutrients based on nitrogen elements such as nitrite and nitrate have long been served as food preservatives in the food industry, as fertilizer in agriculture, and as color formers and rust inhibitors in the chemical industry. Due to the extensive nitrite and nitrate usage, the leakage or pollution discharge resulted in a large amount wasted in water sources and soil. As they are highly toxic inorganic pollutant, excess consumption and nitrite exposure can trigger several diseases and damage human health. As a consequence, an urgent need to develop a particular device for detecting and monitoring the presence of nitrite, specifically to measure drinking water quality and control remediation procedures. Owing to the merits of graphene, including broad theoretical surface area, high conductivity at room temperature, and a wider electrochemical window, graphene now serves as an excellent host material for anchoring nanomaterials to enhance the performance of electrochemical applications. There has been rapid progress in developing nitrite and nitrate sensors based on an electrochemical approach with the assistance of graphene-based nanocomposite material as the electrocatalysts. The electrically conductive graphene has high surface areas that allow the deposition of high-density analyte molecules, facilitating better selectivity and high sensitivity compared to other materials. The present review provides an overview on the recent development of electrochemical sensors for detecting nitrates and nitrites using graphene-based nanocomposites as electrocatalysts based on selective reports.

Magnetic nature carbon dots (MNCDs) are fast growing materials with extremely unique physico-chemical properties and physiological ability to extend their applications from separation science to detection and bio-/magnetic resonance imaging applications. Recent studies have revealed that the MNCDs are significantly used as promising agents in analytical chemistry for the separation and identification of trace level target analytes. Further, the MNCDs have been used as probes for bioimaging of cells and magnetic resonance imaging (MRI) of tumors. Due to the lack of comprehensive reviews in this emerging field especially MNCDs applications in analytical chemistry, this review may provide quick guide and reference on the MNCDs-based analytical approaches for the separation and detection of trace level analytes, and bio- and MR- imaging of various cells. In this review article, we will summarize the synthetic approaches for the fabrication of MNCDs. The main part of this proposed review is devoted to the tremendous applications of MNCDs (Fe₃O₄@CDs, metal ion (Fe³⁺, Mn²⁺, Co²⁺ and Gd²⁺)-doped CDs, MnO₂@CDs) in analytical chemistry from separation science to detection and bio- and MR imaging. Finally, we will explore the challenges and future prospects of magneto fluorescent carbon dots in biomedical applications.

The widespread distribution of plastics, their persistence and ability to act as a vector of toxic chemicals has rendered them concerning emergent pollutants. The quantification of these contaminants is highly relevant for the evaluation of anthropogenic impacts on aquatic and terrestrial ecosystems and dependent of the efficacy of methods to separate microplastics from environmental matrices. Little information is available about the microplastic extraction methods on complex samples – i.e. samples with multiple types of matrices. Herein, methods for the separation of microplastics from complex samples are summarized and discussed based on their advantages and drawbacks focused on a comparative analysis of their efficiency on organic matter removal, polymer recovery and preservation of plastic integrity. The efficiency on microplastic recovery and organic matter reduction, as well as the examination of the effects of treatments on plastics are closely linked to the density and digestion approaches selected, the polymer features and the environmental matrix analyzed. High-density salt solutions are more effective for density separation, while oxidative methods have recurrently shown better rates of organic matter reduction (particularly in vegetal-rich samples) and plastic recovery, with little impact on plastics, while 10 % KOH has been described as highly efficient in samples containing animal organic matter. This comparative analysis highlights the benefits and limitations of different approaches for the analysis of microplastics in complex samples which may be helpful for the optimization and harmonization of the methods.

This review reports different approaches for monitoring the presence of organic contaminants in marine environments. From the traditional standard chromatographic methodologies coupled to different detectors to the recent advances in sensor technology, different strategies have been adopted by researchers aiming to provide more comprehensive, realistic and accurate environmental monitoring data sets. Reports on chemical analysis by different techniques of marine water and sediments, using grab and passive sampling techniques, are the most abundant in literature, showing relevant developments. Analysis of the marine biota (biomonitoring) has also been widely used as a proxy for the detection of organic chemicals in seawater, with bivalves being the most used as sentinel specie. Such biomonitoring can provide insights on bioavailability and bioaccumulation of organic pollutants, which is not possible to obtain by water and sediment analysis solely. Furthermore, effect-based methods are also presented as an important approach when it comes to obtain environmental meaningful data, such as potential toxicity and hazards posed by the complex chemical mixtures to local biota. This approach is reported to be a useful tool for screening areas without any previous knowledge on chemical composition, with subsequential qualitative and quantitative characterization being performed by chemical analysis. Finally, some of the most recent developments in sensor and biosensor technology for environmental purposes are also discussed, with some proof-of-concept studies showing promising results. However, further development and validations work is strongly advised prior to the use of those sensing platforms in real field trials.