Analysis Of Environmental Samples Research Articles

Efficient and sustainable microplastics analysis for environmental samples using flotation for sample pre-treatment

• Separation of microplastics from soil with water and air only • Robust, efficient and green sample preparation with a high separation quality • Investigations were performed by using TED-GC-MS and µRaman • Assessment of sample preparation approaches regarding green analytical chemistry Microplastics analysis in solid environmental samples like sediments and soils requires complex preparation steps to eliminate interfering matrix components. This is often combined with the use of highly concentrated, expensive, and environmentally harmful chemicals. These sample preparation methods can be very time-consuming. Hence, with regard to green analytical chemistry, reduction of emissions and hazards, these sample preparation methods should be modified or avoided, and more environmentally friendly methods should be developed. The characterization and evaluation of the optimized hydrophobicity-water/air-based enrichment cell for microplastics (µSEP) are presented in this study. The separation mechanism of µSEP is based on the hydrophobic adhesion of microplastic on finely dispersed upstreaming air bubbles, serving as a sustainable and practical microplastic sample preparation method. The separation mechanism requires only water and air to considerably reduce the matrix for microplastic analysis. Using soil samples as an example, the applicability of the µSEP sample preparation method for the analysis of microplastics by Raman microspectroscopy (µRaman) and thermal extraction-desorption gas chromatography-mass spectrometry (TED-GC-MS) is demonstrated. Within a sample preparation time of 60 minutes, for polyethylene terephthalate (PET), an average recovery of 77% ± 11%, for polystyrene (PS), 42% ± 11%, and for polypropylene (PP) 65% ± 12% was determined. Furthermore, this study evaluates µSEP and other sample preparation methods regarding their ecotoxicological impact based on the recently released software tool AGREEprep. This tool considers ten individual criteria to cover influencing factors of green analytical chemistry.

Portable X-ray Fluorescence (pXRF) as a Tool for Environmental Characterisation and Management of Mining Wastes: Benefits and Limits

Portable X-ray fluorescence (pXRF) is one of the main geochemical techniques employed in multi-elemental analysis screening for contaminated sites management. As the confidence of pXRF analyses are matrix-specific, efforts are made to provide studies of pXRF quality on different geochemical datasets, focusing on less investigated elements such as mercury (Hg) and antimony (Sb), to help both new and experienced users. The analysis of environmental solid samples from two decommissioned mining sites in NE Italy, characterised by Pb-Zn and (Hg-rich) Cu-Sb ore deposits, were prepared with two different protocols and compared with traditional destructive analyses. Sample composition was found strictly dependent to the occurrence of false positives and overestimation at low concentrations. In contrast, milling the sample did not produce major variations in the overall quality. Lead (Pb), Sb, and Zn reached the definitive data quality in at least one of the two datasets. Consequently, as far as a thorough QA/QC protocol is followed, pXRF can rapidly produce chemical data that is as accurate as that produced by destructive standard laboratory techniques, thus allowing to identify potential sources of contamination that could be reprocessed for the extraction of valuable elements and mitigating the dispersion of contaminants and ecological or health risks.

3D electrochemical device obtained by additive manufacturing for sequential determination of paraquat and carbendazim in food samples

Pesticides are heavily employed compounds protecting crops, however, these compounds can be extremely harmful to human health. Once the monitoring of pesticides in foods is of great importance, in this work we propose a ready-to-use electrochemical sensor made with 3D printing technology, capable of detecting paraquat and carbendazim in sequential analysis. The proposed electrodes are lab-made and of easy obtention, composed of graphite on a polylactic acid matrix, and provided great results for the analysis of paraquat and carbendazim in honey, milk, juice, and water samples. The sequential analysis of paraquat and carbendazim was proposed, providing optimal analysis of both compounds individually when both are present in a mixture. Limits of detection of 0.01 and 0.03 µmol/L for paraquat and carbendazim, respectively. Recovery tests attested to the suitability of the method, ranging from 94.5 to 113.7 %, and the suitability of 3D printing for environmental and food samples analysis.

Environmental water extracts differentially activate zebrafish and human nuclear progesterone receptors

Many reports on anti-progestogenic activities in aquatic environments have been published in the past decade. These are monitored mainly by in vitro reporter gene bioassays based upon the human progesterone receptor (PR). However, results obtained by some human in vitro bioassays may not be relevant for aquatic animals, especially fish. The present work aimed to detect fish (anti-)PR activity in waste- and receiving surface waters. In parallel, human (anti-)PR activity was analysed to determine if there was any connection between human and fish (anti-)PR activities. Finally, (anti-)PR activities were linked to the occurrence of progestins in water samples. Human PR agonistic activity was detected in all wastewater and most receiving surface water samples. Nevertheless, zebrafish PR (zfPR) agonistic activity was found in only two influent wastewater samples (max. 117 ng/L 17α,20β-dihydroxy-4-pregnen-3-one [DHP] equivalents). Analysed synthetic progestins and progesterone accounted for 14 % to 161 % of detected human PR (hPR) agonistic activity in water samples. Progesterone also contributed significantly to zfPR agonistic activity (up to 10 %) in raw wastewater. The anti-hPR activity was detected also in most wastewater and some surface water samples, but synthetic progestins did not trigger anti-zfPR activity in excess of LOQ values. In addition, altrenogest, dienogest, and ulipristal acetate were tested for their potency to zfPR for the first time. The activity analyses of both pure substances and environmental samples showed that human and zebrafish progesterone receptors are differentially activated. Therefore, results based on human PR in vitro bioassays could not predict fish PR activities in the environment.

Novel fast pesticides extraction (FaPEx) strategy coupled with UHPLC-MS/MS for rapid monitoring of emerging pollutant fipronil and its metabolite in food and environmental samples

In this work, we demonstrated a new, environmental-friendly and effective sample preparation strategy named ‘in-syringe-assisted fast pesticides extraction (FaPEx)’ technique coupled with LC-MS/MS for the rapid identification and monitoring of emerging pollutant fipronil and its metabolite fipronil sulfone in chicken egg and environmental soil samples. FaPEx strategy comprising of two simple steps. Firstly, the sample was placed in the syringe and extracted using low-volume acetonitrile with NaCl and anhydrous MgSO4 salts. Secondly, the extractant was passed through in-syringe-based solid-phase extraction (SPE) kit containing cleanup sorbents and salt combinations (C18, primary secondary amine, and anhydrous MgSO4) for the cleanup process. Then, the obtained clean extractant was injected into LC-MS/MS for the quantification of target analytes. Various important parameters influencing the FaPEx performances, such as solvent type, salt type, salt amount, sorbent type, and amount, were examined and optimized. The method validation results showed excellent linearity with high correlation coefficients were ≥ 0.99. The estimated LODs were between 0.05–0.07 μg/kg, and LOQs ranged between 0.1–0.25 μg/kg for target analytes in both egg and soil sample matrices, and precision values were ≤7.90%. The developed method was applied to commercial chicken egg samples and environmental soil samples analysis. Spiked recoveries ranged between 88.75–110.91% for egg samples with RSDs ≤7.42% and 82.47–107.46% for soil samples with RSDs <7.37%. These results proved that the developed sample preparation method is a simple, fast, green, low-cost, and efficient method for the analysis of fipronil and its metabolites in food and environmental samples. Thus, this method can be applied as an alternative analytical methodology in routine and standard food and environmental testing laboratories.

Novel database and cut-off value for bacterial amoA gene revealed a spatial variability pattern of the ammonia-oxidizing bacteria community from river to sea

Ammonia-oxidizing bacteria (AOB) catalyze the first step of nitrification, oxidizing ammonia to nitrite, and are characterized by amoA gene encoding ammonia monooxygenase. To analyze the AOB community effectively, an integral taxonomy database containing 14,058 amoA sequences and the optimal cut-off value at 95 % for OTU clustering were determined. This method was evaluated to be efficient by the analysis of environmental samples from the river, estuary, and sea. Using this method, a significant spatial variance of the AOB community was found. The diversity of AOB was highest in the estuary and lowest in the ocean. Nitrosomonas were the predominant AOB in the sediments of the freshwater river and estuary. Nearly all the AOB-amoA sequences belonged to uncultured bacterium in the sediments of deep sea. In general, an integral AOB taxonomic database and a suitable cut-off value were constructed for the comprehensive exploration of the diversity of AOB from river to sea.

Sample preparation and chromatographic separation for Sr, Nd, and Pb isotope analysis in geological, environmental, and archaeological samples

Sample preparation and chromatographic separation for Sr, Nd, and Pb isotope analysis in geological, environmental, and archaeological samples

Environmental DNA

Emilie Didaskalou and colleagues introduce the analysis of DNA form environmental samples.

A microplasma converter-based spectrophotometry and visual colorimetry for nonchromatographic speciation analysis of H2S/SO2 or S2-/[formula omitted] in environmental water samples

Pollution of sulfur compounds could result in serious environmental issues, while the excessive intake tended to damage the respiratory and nervous system of living beings. In this article, a microplasma converter with small size, easy operation and low gas and power consumption was constructed to fulfill the high-efficient oxidation process of H2S to SO2, which was applied to both spectrophotometry and visual colorimetry to achieve a simple and quick nonchromatographic speciation analysis of H2S/SO2 or S2-/SO32-. Especially, analytes were introduced by acidified to vapor, greatly alleviating the matrices interferences, and visual colorimetry could attain direct naked eye detection without expensive instruments and tedious operation procedures. The lowest limit of detection was 3.47 μmol/L for both aqueous S2- and SO32- ions, and the integration of two methods covered a wide detection range of 0.05–7 mmol/L. These developed methods were applied to analysis of real environmental water samples successfully.

Solid-Phase Microextraction-Gas Chromatography Analytical Strategies for Pesticide Analysis.

Due to their extensive use and the globalized commerce of agricultural goods, pesticides have become a global concern. Despite the undoubtful advantages of their use in agricultural practices, their misuse is a threat to the environment and human health. Their analysis in environmental samples and in food products continues to gain interest in the analytical chemistry community as they are challenging matrices, and legal concentration limits are particularly low (in the order of ppb). In particular, the use of solid-phase microextraction (SPME) has gained special attention in this field thanks to its potential to minimize the matrix effect, while enriching its concentration, allowing very low limits of detection, and without the need of a large amount of solvents or lengthy procedures. Moreover, its combination with gas chromatography (GC) can be easily automated, making it a very interesting approach for routine analysis. In this review, advances and analytical strategies for the use of SPME coupled with GC are discussed and compared for the analysis of pesticides in food and environmental samples, hopefully encouraging its further development and routine application in this field.

Multimodal X-ray nano-spectromicroscopy analysis of chemically heterogeneous systems.

Understanding the nanoscale chemical speciation of heterogeneous systems in their native environment is critical for several disciplines such as life and environmental sciences, biogeochemistry, and materials science. Synchrotron-based X-ray spectromicroscopy tools are widely used to understand the chemistry and morphology of complex material systems owing to their high penetration depth and sensitivity. The multidimensional (4D+) structure of spectromicroscopy data poses visualization and data-reduction challenges. This paper reports the strategies for the visualization and analysis of spectromicroscopy data. We created a new graphical user interface and data analysis platform named XMIDAS (X-ray multimodal image data analysis software) to visualize spectromicroscopy data from both image and spectrum representations. The interactive data analysis toolkit combined conventional analysis methods with well-established machine learning classification algorithms (e.g. nonnegative matrix factorization) for data reduction. The data visualization and analysis methodologies were then defined and optimized using a model particle aggregate with known chemical composition. Nanoprobe-based X-ray fluorescence (nano-XRF) and X-ray absorption near edge structure (nano-XANES) spectromicroscopy techniques were used to probe elemental and chemical state information of the aggregate sample. We illustrated the complete chemical speciation methodology of the model particle by using XMIDAS. Next, we demonstrated the application of this approach in detecting and characterizing nanoparticles associated with alveolar macrophages. Our multimodal approach combining nano-XRF, nano-XANES, and differential phase-contrast imaging efficiently visualizes the chemistry of localized nanostructure with the morphology. We believe that the optimized data-reduction strategies and tool development will facilitate the analysis of complex biological and environmental samples using X-ray spectromicroscopy techniques.

Smartphone-integrated dual-emission fluorescence sensing platform based on carbon dots and aluminum ions-triggered aggregation-induced emission of copper nanoclusters for on-site visual detecting sulfur ions

A ratiometric fluorescence strategy was proposed based on carbon dots (CDs) and self-assembled copper nanoclusters (CuNCs) driven by Al3+ ions for S2− detection. Si-CDs/CuNCs@Al3+ exhibits blue and red emission under single excitation. Interestingly, the red emission of the CuNCs was regularly quenched while the blue fluorescence emission of the CDs was preserved after continuous addition of S2−. The fluorescence spectrometer-based S2− linear range is from 0.5 to 40 μM, with a low detection limit (LOD) of 0.16 μM. The fluorescence response of Si-CDs/CuNCs@Al3+ to S2− exhibits a distinct color change process (red to pink to blue), implying feasibility of visual analysis. A portable fluorescence sensing platform was established using the color-to-value conversion function of a smartphone for accurate visualization and quantitative identification of S2− without spectrometer. The fluorescent test strips prepared with Si-CDs/CuNCs@Al3+ can conduct on-site visual analysis of S2− in the water environment more conveniently and quickly. The linear range of S2− detection based on the smartphone-integrated test strip sensing platform is 1–40 μM, and the LOD is 0.42 μM. This work provides a new horizon for target on-site analysis in environmental samples.

Analytical optimization of liquid–liquid extractive spectrophotometric assessment protocol for tetravalent platinum: Analysis of environmental samples and cisplatin

An easy and reliable method is optimized for extractive spectrophotometric assessment of platinum(IV) with 4-(4′-nitrobenzylideneimino)-3-methyl-5-mercapto-1,2,4-triazole as an extractant. The basis of this method is the formation of red platinum(IV) complex with the above reagent in acetate buffer medium (pH 5.0) and extraction in chloroform. Good linearity with regression equation as y = 1.011 × 104 × + 0.002 having correlation coefficient (R2) of 0.998 over concentration up to 17.5 µg mL−1 of platinum(IV) was achieved with apparent molar absorptivity of 1.011 × 104 L mol−1 cm−1. The limit of detection (0.22 µg mL−1), limit of quantification (0.73 µg mL−1) and Sandell’s sensitivity (0.0193 µg cm−2) were also estimated. The interference of various cations was removed by using proper masking agents and consequently by using EDTA and citrate to mask certain transition metals, the method becomes highly specific for platinum(IV), including the effects of platinum group metals. The method is effectively used for determination of platinum(IV) from environmental and real samples such as alloys, catalysts, thermocouple wire and pharmaceutical sample.

The protein scaffold calibrates metal specificity and activation in MerR sensors.

MerR metalloregulators are the central components of many biosensor platforms designed to report metal contamination. However, most MerR proteins are non-specific. This makes it difficult to apply these biosensors in the analysis of real environmental samples. On-demand implementation of molecular engineering to modify the MerR metal preferences is innovative, although it does not always yield the expected results. As the metal binding loop region (MBL) of these sensors has been proposed to be the major modulator of their specificity, we surgically switched this region for that of well-characterized specific and non-specific homologues. We found that identical modifications in different MerR proteins result in synthetic sensors displaying particular metal-detection patterns that cannot be predicted from the nature of the assembled modules. For instance, the MBL from a native Hg(II) sensor provided non-specificity or specificity toward Hg(II) or Cd(II) depending on the MerR scaffold into which it was integrated. These and other evidences reveal that residues outside the MBL are required to modulate ion recognition and transduce the input signal to the target promoter. Revealing their identity and their interactions with other residues is a critical step toward the design of more efficient biosensor devices for environmental metal monitoring.

Dual Lab-in-Syringe Flow-Batch Platform for Automatic Fabric Disk Sorptive Extraction/Back-extraction as a Front End to Inductively Coupled Plasma Atomic Emission Spectrometry.

A novel dual lab-in-syringe flow-batch (D-LIS-FB) platform for automatic fabric-disk-in-syringe sorptive extraction followed by oxidative back-extraction as a front end to inductively coupled plasma atomic emission spectrometry (ICP-AES) is presented for the first time. Sol-gel poly(caprolactone)-poly(dimethylsiloxane)-poly(caprolactone)-coated polyester fabric disks were packed at the top of the glass barrel of a microsyringe pump as an alternative to column preconcentration. Herein lie multiple significant advantages including effectiveness, compactness, lower back-pressure, and lower time of analysis. Copper, lead, and cadmium were used as model analytes for the exploration of the capabilities of the developed platform. The online retained metal-diethyldithiophosphate complexes were eluted using diisopropyl ketone prior to atomization. Undesirable incompatibility of organic solvents for direct injection into the ICP-AES system was overcome ingeniously in a flow manner by oxidative back-extraction of the analytes utilizing a second lab-in-syringe setup. Following its optimization, the D-LIS-FB platform showed excellent linearity, in combination with good method precision (i.e., RSD < 3.4%) and trueness. Moreover, the limits of detection were 0.25 μg L-1 for Cd(II), 0.13 μg L-1 for Cu(II), and 0.37 μg L-1 for Pb(II), confirming the applicability of the proposed system for metal analysis at trace levels. As a proof-of-concept, the developed versatile system was utilized for the analysis of different environmental, food, and biological samples.

Improved biodiversity detection using a large-volume environmental DNA sampler with in situ filtration and implications for marine eDNA sampling strategies

Metabarcoding analysis of environmental DNA samples is a promising new tool for marine biodiversity and conservation. Typically, seawater samples are obtained using Niskin bottles and filtered to collect eDNA. However, standard sample volumes are small relative to the scale of the environment, conventional collection strategies are limited, and the filtration process is time consuming. To overcome these limitations, we developed a new large – volume eDNA sampler with in situ filtration, capable of taking up to 12 samples per deployment. We conducted three deployments of our sampler on the robotic vehicle Mesobot in the Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico and collected samples from 20 to 400 m depth. We compared the large volume (∼40–60 L) samples collected by Mesobot with small volume (∼2 L) samples collected using the conventional CTD rosette – mounted Niskin bottle approach. We sequenced the V9 region of 18S rRNA, which detects a broad range of invertebrate taxa, and found that while both methods detected biodiversity changes associated with depth, our large volume samples detected approximately 66% more taxa than the CTD small volume samples. We found that the fraction of the eDNA signal originating from metazoans relative to the total eDNA signal decreased with sampling depth, indicating that larger volume samples may be especially important for detecting metazoans in mesopelagic and deep ocean environments. We also noted substantial variability in biological replicates from both the large volume Mesobot and small volume CTD sample sets. Both of the sample sets also identified taxa that the other did not – although the number of unique taxa associated with the Mesobot samples was almost four times larger than those from the CTD samples. Large volume eDNA sampling with in situ filtration, particularly when coupled with robotic platforms, has great potential for marine biodiversity surveys, and we discuss practical methodological and sampling considerations for future applications.

Developing a robust method integrating with selective membrane-based preconcentration and signal amplification for field virus detection

Infectious diseases caused by viruses have attracted global concern owing to their rapid spread and catastrophic consequences. Therefore, developing fast and reliable on-site virus detection methods is essential for the prevention and treatment of virus-related diseases. In this study, immunoassays on a membrane, combining virus preconcentration with nanoparticle-based signal amplification, were used to realize the rapid and accurate visual detection of viruses. The biotin–streptavidin scaffolds for target virus preconcentration were established on a membrane, and subsequently a Zika aptamer (Apt) immobilized on the membrane recognized and captured the nonstructural protein 1 of Zika virus (ZIKV-NS1). The probe for detection was synthesized by conjugating the Zika Apt with a high level of horseradish peroxidase on gold nanoparticles. The ZIKV-loaded membrane was incubated with the probes, and the viral signal was amplified as the signal of horseradish peroxidase. In the presence of 3,3,5′,5′-tetramethyl benzidine and hydrogen peroxide, the green color of the probe-coated membrane indicated the level of ZIKV-NS1. Our developed method could reach a detection limit of 5 ng mL−1, and the whole procedure could be completed within 1 h. Analyses of rabbit serum and environmental water samples demonstrated that an immunoassay-based approach on the membrane could accurately determine the level of ZIKV-NS1 against the complicated matrix. Our results suggest that this virus detection method has a high potential for application in clinical and environmental settings.

Insufficiency in functional genomics studies, data, and applications: A case study of bio-prospecting research in ruminant microbiome.

Over the last two decades, biotechnology has advanced at a rapid pace, propelled by the incorporation of bio-products into various aspects of pharmaceuticals, industry, and the environment. These developments have sparked interest in the bioprospecting of microorganisms and their products in a variety of niche environments. Furthermore, the use of omics technologies has greatly aided our analyses of environmental samples by elucidating the microbial ecological framework, biochemical pathways, and bio-products. However, the more often overemphasis on taxonomic identification in most research publications, as well as the data associated with such studies, is detrimental to immediate industrial and commercial applications. This review identifies several factors that contribute to the complexity of sequence data analysis as potential barriers to the pragmatic application of functional genomics, utilizing recent research on ruminants to demonstrate these limitations in the hopes of broadening our horizons and drawing attention to this gap in bioprospecting studies for other niche environments as well. The review also aims to emphasize the importance of routinely incorporating functional genomics into environmental metagenomics analyses in order to improve solutions that drive rapid industrial biocatalysis developments from derived outputs with the aim of achieving potential benefits in energy-use reduction and environmental considerations for current and future applications.

Fe3O4@SiO2@VAN Nanoadsorbent Followed by GC-MS for the Determination of Polycyclic Aromatic Hydrocarbons at Ultra-Trace Levels in Environmental Water Samples.

In the present study, silica-coated magnetic nanoparticles functionalized with vancomycin (Fe3O4@SiO2@VAN) were synthesized. The Fe3O4@SiO2@VAN nanocomposite was used as a sorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from environmental water, followed by GC-MS. The nanocomposite was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and nitrogen sorption. Various experimental parameters were optimized, including extraction condition and desorption condition. Results show that Fe3O4@SiO2@VAN combined the advantages of nanomaterials and magnetic separation technology, showing excellent dispersibility and high selectivity for PAHs in environmental water sample. Under the optimal extraction conditions, an analytical method was established with the sensitive limit of detection (LOD) of 0.03–0.16 μg L−1. The method was successfully applied for the analysis of environmental water samples. The relative standard deviations (%) were in the range of 0.50–12.82%, and the extraction recovery (%) was in the range of 82.48% and 116.32%. MSPE-coupled gas chromatography–mass spectrometry quantification of PAHs is an accurate and repeatable method for the monitoring of PAH accumulation in environmental water samples. It also provides an effective strategy for the tracing and quantification of other environmental pollutants in complex samples.

Property of arylsulfatase and β-glucuronidase extracted from digestive tracts of Cipangopaludina chinensis and their cleavage performance on conjugated natural estrogens.

Arylsulfatase and β-glucuronidase are the two substantial enzymes having a significant role in the cleavage of conjugated natural estrogens (C-NEs). The present study reports that arylsulfatase and β-glucuronidase have been abundantly found in the digestive tracts of Cipangopaludina chinensis; in which, their corresponding activities were 60 and 5 U/g wet waste, respectively. The arylsulfatase from Cipangopaludina chinensis could show high activity at low temperatures. Hence, its activity still remained at 53.2% of maximal activity even at an extremely low temperature of 4 ℃; while the corresponding activities of arylsulfatase from Helix pomatia or activated sludge were less than 20% and 10%, respectively. The arylsulfatase and β-glucuronidase from Cipangopaludina chinensis could efficiently cleave C-NEs suggesting that they could be alternative enzymes derived from Helix pomatia that are used for cleavage of conjugated compounds in environmental or biological sample analysis. Meanwhile, they might also be used to enhance the cleavage of C-NEs in municipal wastewater.