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The development of disposable sensors that can be easily adapted to every analytical problem is currently a hot topic that is revolutionizing many areas of science and technology. The need for decentralized analytical measurements at real time is increasing for solving problems in areas such as environment pollution, medical diagnostic, food quality assurance, etc., requiring fast action. Despite some current limitations of these devices, such as insufficient detection capability at (ultra)trace level and risk of interferent effects due to matrix, they allow low-cost analysis, portability, low sample consumption, and fast response. In the last years, development of paper-based analytical devices has undergone a dramatic increase for on-site detection of toxic metal ions and other pollutants. Along with the great availability of cellulose substrates, the immobilization of receptors providing enhanced recognition ability, such as a variety of nanomaterials, has driven the design of novel sensing approaches. This review is aimed at describing and discussing the different possibilities arisen with the use of different nanoreceptors (e.g., plasmonic nanoparticles, quantum dots, carbon-based fluorescent nanoparticles, etc.) immobilized onto cellulose-based substrates for trace element detection, their advantages and shortcomings. [ABSTRACT FROM AUTHOR]

African swine fever virus (ASFV) is a highly pathogenic and rapidly disseminated virus with strong viability in the environment, suggesting the importance of environmental detection for prevention and control in all the pig industry. However, the detection results of environmental swabs cannot always reflect the accurate status of viral pollution, leading to persistent ASFV environmental contamination. In this study, we developed an ASFV eluant with higher environmental ASFV detection efficiency relative to 0.85% saline solution, which obtains the patent certificate issued by the China Intellectual Property Office (patent number:202010976050.9). qPCR analysis showed that in the environmental swab samples, the number of viral copies was 100 times higher for the ASFV eluant treatment than the traditional eluant treatment (0.85% saline solution). And besides, the high sensitivity of the ASFV eluant had be verified in a slaughterhouse environmental sampling detection. In soil samples, the ASFV eluent showed the same extraction effect as the TIANamp Soil DNA Kit, in contrast to no extraction effect for 0.85% saline solution. Simultaneously, this eluent could protect ASFV from degradation and allow the transportation of samples at ambient temperature without refrigeration. In clinical practice, we monitored the environmental contamination condition of the ASFV in a large-scale pig farm. The results shown that the ASFV load decreased after every disinfection in environment. This study provides an effective solution for surveilling the potential threat of ASFV in environment. Key points: The ASFV eluant can significantly improve the positive detection rate in environmental samples in clinical practice. The ASFV eluant is economical and convenient compared to commercial kit.. The ASFV eluant can provide a caution for the environmental safety for China's pig industries, slaughter houses, and transportations and facilitate ASFV eradication. [ABSTRACT FROM AUTHOR]

A new construction of a potentiometric sensor was introduced for the first time. It relies on the use of two membranes instead of one, as in the well-known coated-disc electrode. For this purpose, a new electrode body was constructed, including not one, but two glassy carbon discs covered with an ion-selective membrane. This solution allows for the sensor properties to be enhanced without using additional materials (layers or additives) on the membrane. The new construction is particularly useful for in situ measurements in environmental samples. Two ion-selective polymeric membranes were used, namely H+ and K+-selective membranes, to confirm the universality of the idea. The tests conducted included chronopotentiometric tests, electrochemical impedance spectroscopy, and potentiometric measurements. The electrical and analytical parameters of the sensors were evaluated and compared for all tested electrodes to evaluate the properties of the planar electrode versus previously known constructions. Research has shown that the application of two membranes instead of one allows for the resistance of an electrode to be lowered and for the electrical capacitance to be elevated. Improving the electrical properties of an electrode resulted in the enhancement of its analytical properties. The pH measurement range of the planar electrode is 2–11, which is much wider in contrast to that of the single-membrane electrode. The linear range of the K+-selective planar electrode is wider than that of the coated-disc electrode and equals 10−6 to 10−1 M. The response time turned out to be a few seconds shorter, and the potential drift was smaller due to the application of an additional membrane in the electrode construction. This research creates a new opportunity to design robust potentiometric sensors, as the presented construction is universal and can be used to obtain electrodes selective to various ions. [ABSTRACT FROM AUTHOR]

In this work, a procedure based on dispersive liquid-liquid micro-extraction for lead (Pb) pre-concentration and quantification in an environmental matrix by flame atomic absorption spectroscopy (FAAS) was applied. A case-study approach was chosen to obtain further in-depth information on the Pb levels. The green chemistry principles have been applied for the pretreatment and preparation of real samples by focusing on some features such as the volume of reagents/sample, employ of energy efficient equipment, and production of waste. A univariate strategy was utilized to achieve the optimum extraction conditions. 1750 mL of acetonitrile containing 100 mL of carbon tetrachloride, were rapid injection into: 12.0 mL of a sample solution adjusted the pH at 9.0 and 0.07% (m v-1) Dithizone. The estimated limits of detection (LOD) and quantification (LOQ) under optimum conditions were 2.85 and 9.5 mg L-1, respectively. The enrichment factors EFs were found to be 60.6 (aqueous standards/DLLME-FAAS) and 30.8 (matrix matched/DLLME-FAAS). It was applied for the analyzing eleven environmental samples. The detectable Pb levels for water samples were ranged from 1.87 to 8.11 mg L-1, while in solid samples were ranged 0.39e4.66 mg g-1. The relative standard deviation for three concentrations (low, medium, and high) were found to be 10.64, 6.87, and 2.7, respectively. The presented system was validated by analyzing eleven environmental samples (water, bivalve molluscs, lettuce, and medicinal plants). The results indicated that high recoveries were obtained in the range of 92e104 %. The lead concentration was found in these samples always lower than permissible maximum levels stipulated by Iraqi Standards Specifications 2009 (number 417) for neutral water. The DLLME/FAAS procedure has proven to be a fast, simple, low-cost, and efficient analytical protocol, therefore allowing for employing this protocol in routine analysis of trace metals in such matrixes. [ABSTRACT FROM AUTHOR]

Portable smartphone platform offers a new strategy for on-site and visual quantitative detection of ammonium nitrogen in soil and wastewater samples. [Display omitted] • OPA/K 2 SO 3 /R-QDs and OPA/K 2 SO 3 based sensor have been respectively used for determination of low and high concentration range of NH 4 + via two response modes. • The color responses toward the NH 4 + concentrations have been systematically studied. • The proposed strategy can realize visual quantitative detection of NH 4 + in real samples. • Portable smartphone platform brings great convenience for on-site detection of NH 4 +. Ammonium (NH 4 +) is crucial for plant growth as well as various industrial processes, the accurate and field measurement of the NH 4 + level is of great significance for agricultural precision fertilization and water quality monitoring, but excessive amounts of ammonium can lead to eutrophication of aqueous environments. Herein, the ability of the proposed probe solution and test paper to colorimetric change towards high-concentration NH 4 + and ratiometric fluorescence response to low-concentration NH 4 + has been developed for visual detection of ammonium in real samples. Specifically, high concentration of NH 4 + (0.5–7 mM) could interact with the o-phthalaldehyde (OPA) in presence of K 2 SO 3 , resulting in the colorimetric transition from colorless to wine-red with increasing the NH 4 + concentration. Subsequently, the addition of the red-emitting CdTe QDs (R-QDs) constructed the OPA/K 2 SO 3 /R-QDs ratiometric fluorescent probes for low-concentration NH 4 + (less than 1 mM) sensing with a limit of detection (LOD) down to 18 nM, accompanied by a distinct fluorescence color shift from red to blue under UV light. Furthermore, the visualization detection integrated with smartphone was converted to data information (RGB value) through a Color Recognizer APP and successfully used for visual quantitative identification of NH 4 +. Actually, the proposed probe solution and test paper have been applied to the determination of NH 4 + in soil extracts and wastewater samples. Compared with the standard methods, this established strategy can supply stable and reliable detection results, and allow fast sensing at room temperature, exhibiting great application potential for visual on-site detection of NH 4 + at different concentration ranges in environmental samples. [ABSTRACT FROM AUTHOR]

Countless deleterious effects on human health and the environment are promoted by the action of air pollutants. Thus, it is necessary the development of analytical methods to identify and quantify efficiently ions present in atmospheric particulate matter. This study proposes a new analytical methodology for simultaneous quantification of 12 organic ions (Lactate, Acetate, Propionate, Formate, Butyrate, Methanesulfonate, Pyruvate, Monochloroacetate, Trifluoroacetate, Succinate, Oxalate and Citrate), 12 inorganic anions (fluoride, bromate, chloride, nitrite, bromide, nitrate, sulfite, sulfate, tungstade, molybdate, phosphate and chromate) and 7 cations (lithium, sodium, ammonium, potassium, magnesium, calcium and strontium) using ion chromatography coupled to conductivity detection. The optimization of the proposed method was performed univariate and validation was done according to IUPAC recommendations; LOD and LOQ varied between 12 to 114 pg m-3 and 35 to 342 pg m-3 respectively, showing recovery values between 89% to 109% and R2 between 0.9979 and 0.9999 for the 31 main ions studied. Ions were successfully determined in environmental samples of particulate material in the 10 µm and 2.5 µm fractions. This method was considered a comprehensive, accurate, fast and robust procedure for the study of ions in samples of atmospheric particulate matter. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Industrial Hygiene & Toxicology / Arhiv za Higijenu Rada I Toksikologiju is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to human activities, the concentrations of organometallic compounds in all parts of the environment have increased in recent decades. The toxicity and some biochemical properties of mercury and tin present in the environment depend on the concentration and chemical form of these two elements. The ever-increasing demand for determining compounds at very low concentration levels in samples with complex matrices requires the elimination of interfering substances, the reduction of the final extract volume, and analyte enrichment in order to employ a detection technique, which is characterised by high sensitivity at low limits of quantification. On the other hand, in accordance with current trends, the analytical procedures should aim at the miniaturisation and simplification of the sample preparation step. In the near future, more importance will be given to the fulfilment of the requirements of Green Chemistry and Green Analytical Chemistry in order to reduce the intensity of anthropogenic activities related to analytical laboratories. In this case, one can consider the use of solvent-free/solvent-less techniques for sample preparation and microextraction techniques, because the use of the latter leads to lowering the quantity of reagents used (including solvents) due to the reduction of the scale of analysis. This paper presents an overview of microextraction techniques (SPME and LPME) used in the procedures for determining different chemical forms of mercury and tin. [ABSTRACT FROM AUTHOR]

Copyright of Ecological Chemistry & Engineering S / Chemia i Inzynieria Ekologiczna S is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite the widespread use of the USEPA method (U.S. Environmental Protection Agency, 40 CFR 136 Appendix B) for the determination of method detection limit (MDL), criticisms have been raised that the method does not account for measurement bias and outliers that subsequently lead to a common misunderstanding of the requirement for the determination of MDL. This paper demonstrates that it is difficult to follow the USEPA method for verifying the MDL for analysis involving multiple metals and proposes a precision and bias criterion for determining the MDL. A multiple-point fitted profile, based on the correlation between relative standard deviation (RSD) and concentration, is used to derive a robust MDL value. Representative examples of As, Ca, Cr, and Cu are used to illustrate this procedure. A procedure for identifying outliers is also discussed. [ABSTRACT FROM AUTHOR]

Owing to their favorable properties, ionic liquids have recently gained recognition as possibly environmentally benign solvents. Now among the most promising industrial chemicals, they have already been labeled “green”, but this appellation seems due entirely to their very low vapor pressure. This growing interest in the various applications of ionic liquids will soon result in their presence in the environment. Therefore, reliable analytical tools for the environmental analysis of ionic liquids need to be developed urgently. This paper presents a newly developed analytical procedure for the enrichment of 1-alkyl- and 1-aryl-3-methylimidazolium ionic liquids from water samples. The method is based on cation exchange solid-phase extraction followed by selective elution. Pre-concentrated samples are subjected to high-performance liquid chromatography (HPLC) with an advanced methodology for qualitative and quantitative analysis. The overall procedure was verified by using standard spiked samples of tap water, seawater, and freshwater. [ABSTRACT FROM AUTHOR]

This paper reviews derivatisation processes applied in chromatographic determination of acidic herbicides (with carboxyl and phenol groups), mainly in aqueous environmental samples. The discussion focuses on the basic derivatisation reactions used to convert herbicides to derivatives to make them analysable by gas chromatography, and possibly to reduce detection limits and/or increase extraction recovery from aqueous samples. The reactions are transesterification, esterification, silylation, alkylation, and extractive and pyrolytic alkylation. The reagents used to conduct the reactions are numerous. Diazomethane is a very efficient methylation reagent but explosive and toxic. Methyl iodide also ensures rapid and efficient methylation. Benzyl bromide can be used directly in water but derivatisation yield is low and reproducibility is poor. Butyl chloroformate and dimethyl sulfite can also be used for derivatisation in water, and acetic anhydride can be used for in-situ derivatisation of phenolic herbicides. For increasing selectivity of GC detection pentafluorobenzyl bromide (for ECD) and (2-cyanethyl)dimethyl(diethylamino)silane (for NPD) have been applied. Very characteristic ions are produced in mass spectra if silyl groups are introduced, e.g. by using bis(trimethylsilyl)trifluoroacetamide. Tetramethylammonium, trimethylphenylammonium, tetraalkylammonium, and trimethylsulfonium hydroxides and salts can by used for derivatisation at elevated temperature in the GC injection port. Extractive alkylation is relatively efficient if tetraalkylammonium salts with long chain alkyl groups are used. [ABSTRACT FROM AUTHOR]

Ingestion of polonium-210 from environmental media and food can cause serious health hazards (e.g., gastrointestinal symptoms, tumours, etc.) and has been a public health concern worldwide since the 2006 poisoning of Agent Litvinenko 210Po in Russia. With the development of uranium mining and applications of nuclear technology in recent decades, the radioactive hazards posed by 210Po to living organisms and the environment have become increasingly prominent. In order to strengthen the monitoring of environmental 210Po and protect both the environment and human health, a series of explorations on the methods of 210Po determination have been ongoing by researchers across the globe. However, previous reviews have focused on individual sample types and have not provided a comprehensive account of environmental, food, and biological samples that are closely related to human health. In this work, the sources, health hazards, chemical purification, and detection methods of trace 210Po in different sample types are systematically reviewed. In particular, the advantages and disadvantages of various pretreatment methods are compared, and relevant domestic and international standards are integrated, which puts forward a new direction for the subsequent establishment of rapid, simple, and efficient measurement methods. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUR) are a group of polymers synthesized from different diisocyanate and polyol monomers resulting in a countless number of possible structures. However, the large market demand, and the variety of application fields justify the inclusion of PUR in microplastic (MP) investigation. This study aimed at providing comprehensive information on PUR within MP analysis by pyrolysis–gas chromatography-mass spectrometry to clarify whether (i) it is possible to make a reliable statement on the PUR content of environmental samples based on a few pyrolysis products and (ii) which restrictions are required in this context. PUR were managed as subclasses defined by the diisocyanates employed for polymer synthesis. Methylene diphenyl diisocyanate (MDI)- and toluene diisocyanate (TDI)-based PUR were selected as subclasses of greatest relevance. Different PUR were pyrolyzed directly and under thermochemolytic conditions with tetramethylammonium hydroxide (TMAH). Distinct pyrolytic indicators were identified. The study supported that the use of TMAH greatly reduced the interactions of pyrolytic MP analytes with the remaining organic matrix of environmental samples and the associated negative effects on analytical results. Improvements of chromatographic behavior of PUR was evidenced. Regressions (1–20 µg) showed good correlations and parallelism tests underlined that quantitation behavior of different MDI-PUR could be represented by the calibration of just one representative with sufficient accuracy, entailing a good estimation of the entire subclass if thermochemolysis were used. The method was exemplary applied to road dusts and spider webs sampled around a plastic processing plant to evaluate the environmental spread of PUR in an urban context. The environmental occurrence of MDI-PUR as MP was highly influenced by the proximity to a potential source, while TDI markers were not observed. [ABSTRACT FROM AUTHOR]

Plastic pollution has become one of the most critical environmental issues, as rapidly increasing production, compounded by persistence of plastic wastes in the environment, are outpacing efforts to keep ecosystems plastic-free. A switch to plastics more amenable to microbial attack is one of several possible responses. Against this background, the current study describes the isolation, enumeration and polyphasic characterization of plastic-degrading bacteria present in Norwegian terrestrial and aquatic habits. It shows that these bacteria are present in relatively high numbers, and that plastic-degrading capabilities are found in several taxa, most especially Streptomyces. Some isolates wereable to degrade several plastics. Notably, a Rhodococcus sp. and a Streptomyces sp. degraded, respectively, four and six of the eight plastics investigated and a number of other polymers relevant for plastic blends. The paper also has a methodological aspect, presenting various approaches for assaying plastic-degrading properties and a PCR/sequencing-based approach for the identification of potential polyethylene terephthalate-degrading genes. A candidate gene was detected in several Streptomyces isolates. The study shows that Norwegian environments are a rich source of bacteria with the ability to degrade bioplastics possibly representing a natural remediation capacity, as well as a potential source of useful enzymes. [ABSTRACT FROM AUTHOR]

The gamma spectrometry of environmental samples poses a series of specific problems for the practitioner. The determination of full energy peak efficiencies is, in the case of environmental samples, one of the greatest challenges. In this paper, the calibration of two HPGe detectors for environmental samples in Marinelli beakers was performed using the newly developed MEFFTRAN software. The results obtained with MEFFTRAN were compared to the experimental efficiencies measured using the calibration sample produced at the Laboratory for Radiation and Environment Protection, Institute for Nuclear Sciences Vinca, Belgrade, in order to confirm the validity of the calculation. It is shown that calculated and experimental efficiencies are in good agreement with the discrepancies from −3.9% to +1.5%. The results were also validated by measuring secondary reference materials provided by the IAEA within several interlaboratory proficiency tests. The activity concentration of the radionuclides in the secondary reference materials was determined using the efficiency obtained by MEFFTRAN and compared with the target value given by the IAEA. All the results in materials provided by the IAEA were acceptable except one, proving that MEFFTRAN produces satisfactory results. [ABSTRACT FROM AUTHOR]

The wide-spread usage of ciprofloxacin (CIP) resulted in its presence in different parts of the ecosystem. Thus, a simple, reliable, on-spot detection method for CIP is required in environmental context. Herein, a colorimetric assay is developed for the detection of CIP based on the branched polyethyleneimine (PEI) conjugated silver nanoparticles (PEI-AgNPs). AgNPs are prepared using PEI as stabilizing agent following a simple one-pot two-phase procedure. The prepared PEI-AgNPs are subsequently used for an efficient and selective detection of CIP. The characteristic yellow colour of PEI-AgNPs changed to colourless when CIP was added which was further confirmed by quenching in the intensity of the SPR (surface plasmon resonance) band (hypochromic shift). The proposed method is efficient for the quantitation of CIP in a linear dynamic range (LDR) of 0.1–200 µM with a limit of detection (LOD) of 0.038 µM, and limit of quantification (LOQ) of 0.12 µM. The developed method is selective, efficient, and sensitive to CIP in the presence of numerous interfering species and in real biological, environmental, and commercial pharmaceutical samples. Excellent performance of the proposed method compared to UV-Vis spectroscopy and UPLC in environmental, biological, and commercial pharmaceutical samples is demonstrated. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine an easy and fast method to calculate efficiencies in different volumes, in the same counting geometry, for gamma-ray spectrometry technique. Reference Material Soil IAEA 326 was packed in a 100 mL capacity polyethylene bottle with different masses and volumes, and sealed for about four weeks, prior measurement, in order to ensure that radioactive equilibrium had been reached between 226Ra and its progeny. After this time, they were measured by gamma-ray spectrometry with a hyper-pure germanium detector. The masses of the reference material used were 25, 60, 80, 95 and 128g. The energies of gamma-rays used in this paper are recommended due to the considerations: gamma intensity value, peak quality, spectral region without interference and the gamma- ray energies of the 238U and 232Th series very important for determining the natural radioactivity. The efficiency values obtained compared to the adjusted efficiency values were similar and presented a good correlation coefficient. The performance was acceptable for all different masses studied, indicating results consistent for the method. The proposed method could be useful as a tool for laboratories, dealing with of samples on a routine basis, by reducing the cost on the purchase of another counting geometry and optimizing the use of the detection system, thus improving their performance.

Microplastic particles (MP) are efficiently retained in wastewater treatment plants and enriched in sewage sludge. For monitoring MP contents in wastewater systems, sewage sludge is thus well suited, but also requires an isolation of MP from the sludge matrix, as other sewage sludge components may interfere with the MP identification and quantification. Although organic matter in sludge samples can be removed through acid and enzymatic digestion procedures, cellulose - mainly from toilet paper - remains in the digests, due to its high chemical resistivity and similar density to MP. We apply the separation concept of magnetic seeded filtration to isolate MP through selective hetero-agglomeration with magnetic seed particles. MP and cellulose differ in their hydrophobic properties and we investigate to what extent these differences can be exploited to selectively form MP-magnetite hetero-agglomerates in the presence of cellulose. These hetero-agglomerates are subsequently separated using a magnet. Five MP types (Polyethylene terephthalate (PET), polypropylene (PP), low density polyethylene (LDPE), polyvinyl chloride (PVC) and polystyrene (PS)) and cellulose particles were mixed in different combinations with both hydrophilic and hydrophobic (silanized) magnetite particles. PET, PP, LDPE and PS only poorly agglomerated with pristine (hydrophilic) magnetite, but efficiently formed hetero-agglomerates with hydrophobic magnetite and were successfully removed from suspensions (80−100%). PVC agglomerated more efficiently with pristine than with hydrophobic magnetite and cellulose only agglomerated to a limited extent with either hydrophilic or hydrophobic magnetite, resulting in a high process selectivity. Results from experiments conducted at different ionic strengths and with hydrophilic and hydrophobic magnetite suggests that the agglomeration process was dominated by hydrophobic interactions. Enzymatic and oxidative treatment of the MP only marginally affected the separation efficiencies and (treated) MP spiked to sewage sludge extracts were successfully recovered using magnetic seeded filtration.

In this research, a preconcentration procedure was developed for the determination of silver in environmental samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). During the preconcentration step, bentonite was used as a cheap solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction. The experimental parameters including pH of the sample solution, bentonite amount, and ultrasonication time as well as the main parameters of HR-CS GFAAS were investigated. The limit of detection was 0.01 µg/L, and the achieved preconcentration factor was 34. The relative standard deviation was 5%. The accuracy of this method was validated by analyses of NIST SRM 2709 (San Joaquin soil), NIST SRM 2711 (Montana soil), and NIST SRM 1643e (trace elements in water) certified reference materials. The proposed method was successfully applied for the determination of silver in soil and water samples. [ABSTRACT FROM AUTHOR]

The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector), ultraviolet–visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities. [ABSTRACT FROM AUTHOR]

The presence of pollutants in soil and water has given rise to diverse analytical and biological approaches to detect and measure contaminants in the environment. Using bacterial cells as reporter strains represents an advantage for detecting pollutants present in soil or water samples. Here, an Escherichia coli reporter strain expressing a chromoprotein capable of interacting with soil or water samples and responding to DNA damaging compounds is validated. The reporter strain generates a qualitative signal and is based on the expression of the coral chromoprotein AmilCP under the control of the recA promoter. This strain can be used simply by applying soil or water samples directly and rendering activation upon DNA damage. This reporter strain responds to agents that damage DNA (with an apparent detection limit of 1 µg of mitomycin C) without observable response to membrane integrity damage, protein folding or oxidative stress generating agents, in the latter case, DNA damage was observed. The developed reporter strain reported here is effective for the detection of DNA damaging agents present in soils samples. In a proof-of-concept analysis using soil containing chromium, showing activation at 15.56 mg/L of Cr(VI) present in soil and leached samples and is consistent with Cr(III) toxicity at high concentrations (130 µg). Our findings suggest that chromogenic reporter strains can be applied for simple screening, thus reducing the number of samples requiring analytical techniques. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are nowadays emerging as alternative green solvents for various technological applications. In this context, their environmental impacts need to be assessed, and relatively simple and reproducible analytical techniques are required in order to do this. These must be applicable not only to different natural matrices but also to the very low concentrations likely to be present in environmental systems. Moreover, in the case of solid environmental samples, liquid–solid extraction procedures are prerequisite for gaining further insight into IL distribution in these matrices. This paper reports on extraction methods for isolating IL residues from a number of plants, seeds and soils. The efficiency of five organic and inorganic acids in these extractions ranged from 70.2% to 83.5%, depending on the matrix and acid used. IL recovery rates were highest for phosphoric and trifluoroacetic acids. Recoveries of alkylimidazolium IL from all the plant matrices increased with alkyl chain length. The inference from this study is that IL polarity and steric hindrance both influence the mechanism of their sorption onto the plant matrix, which has a significant impact on the extraction efficiency. Saturated ammonium chloride mixed with a large quantity of methanol was the most effective solvent for extracting soil-bound ILs. The extraction efficiency is inversely proportional to the distribution coefficients of particular soils: the higher the value of K d, the lower the recovery rate. Both methods of extraction were validated for their analytical performance parameters. [Copyright &y& Elsevier]

A highly sensitive and very simple spectrophotometric flow-injection analysis (FIA) method for the determination of iron(III) at low concentration levels is presented. The method is based on the measurement of absorbance intensity of the red complex at 410 nm formed by iron(III) and diphenylamine-4-sulfonic acid sodium salt (DPA-4-SA). It is a simple, highly sensitive, fast, and low cost alternative method using the color developing reagent DPA-4-SA in acetate buffer at pH 5.50 and the flow-rate of 1 mL min−1 with the sample throughput of 60 h−1. The method provided a linear determination range between 5 μg L−1 and 200 μg L−1 with the detection limit (3S) of 1 μg L−1 of iron(III) using the injection volume of 20 μL. FIA variables influencing the system performance were optimized. The amount of iron(III) and total iron in river and seawater samples was successfully determined. Repeatability of the measurements was satisfactory at the relative standard deviation of 3.5 % for 5 determinations of 10 μg L−1 iron(III). The accuracy of the method was evaluated using the standard addition method and checked by the analysis of the certified material Std Zn/Al/Cu 43 XZ3F. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a rapid and quantitative sequential radiochemical separation method for the Pu, Am, U and Np nuclides in radioactive waste samples as well as environmental samples in a hydrochloric acid medium with an anion exchange resin. From the recovery test for the actinides in acid solutions, the Pu, Am, Np and U isotopes were more rapidly purified from the actinides in a hydrochloric acid solution with the anion exchange resin than in a nitric acid solution with the anion exchange resin and TRU resin. Sequential separation method of the Pu, Np, Am and U isotopes was applied to IAEA reference samples, where the activity concentrations of the 239,240Pu, 241Am and 238U in the IAEA-375 and IAEA-326 soils were close to the reference values reported by the IAEA. [Copyright &y& Elsevier]

In this work, the applicability of direct analysis in real time coupled to accurate mass spectrometry (DART-MS) to the quantitative determination of triclosan (TCS) in samples with increasing complexity, from personal care products to extracts from sewage, is investigated. In the first term, DART-MS spectra of TCS as free phenol and as derivatized species are characterized; thereafter, the effects of several instrumental variables in the detectability of TCS (i.e., temperature, solvent, and compound holder) are discussed. Under final selected conditions, TCS was determined from its [M-H]− ions, without need of derivatization, attaining an instrumental limit of quantification of 5 ng mL−1, with a linear response range up to 1000 ng mL−1. Complex matrices, such as solid-phase extracts obtained from environmental water samples, moderately inhibited the ionization efficiency of TCS, with signal attenuation percentages in the range of 6 to 57%, depending on the sample type and on the concentration factor provided by the SPE procedure. The accuracy of results obtained by DART-MS was evaluated using liquid chromatography (LC) with MS detection; in both cases, a time-of-flight (TOF) MS instrument was employed for the selective determination of the [M−H]− ions of TCS (m/z values 286.9439 and 288.9410) using a mass window of 20 ppm. DART-MS did not only provide enough sensitivity to detect the presence of TCS in environmental samples (raw and treated wastewater as well as freeze-dried sludge), but also measured concentrations matched those determined by LC-ESI-TOF-MS, with only slightly higher standard deviations. During analysis of personal care products, containing much higher concentrations of TCS in a less complex matrix, both techniques were equivalent in terms of accuracy and precision. [ABSTRACT FROM AUTHOR]

A method based on supramolecular liquid phase microextraction has been developed for the preconcentration and determination of trace levels of Sudan I. 1-decanol and tetrahydrofuran were used as supramolecular solvent components. Trace levels of Sudan I were extracted into the extraction solvent phase at pH = 4.0 Analytical parameters such as pH value, supramolecular solvent volume, ultrasonication, centrifugation, model solution volume, matrix effects have been optimized. The limit of detection and the limit of quantification values for Sudan I were calculated as 1.74 μg L-1 and 5.75 μg L-1, respectively. In order to determine the accuracy of the method, addition and recovery studies were carried out to environmental samples. [ABSTRACT FROM AUTHOR]

Emerging contaminants are a heterogeneous group of chemicals that includes daily personal care products and pharmaceuticals (PPCPs), flame retardants, endocrine disrupting chemicals (EDCs) and nanoparticles (NPs) present in environment which are unregulated. In this review are presented the methods of analysis conducted by INCD-ECOIND regarding some classes of emerging contaminants (neonicotinoids compounds, beta-blockers) that are not mentioned in the legislation, in different types of environmental samples (influent and effluent). The paper presents the selective solid phase extraction (SPE) methods for isolating the compounds of interest from aqueous matrices and the main operating parameters of the separation process. Then, the compounds were subjected to liquid phase chromatographic separation with mass spectrometric detection (UHPLC-MS/MS). Thus, the main instrumental operating parameters used for the analytical determination of the emerging contaminants studied are presented. Finally, the methods were applied in the determination of compounds from different categories of water, carrying out studies on the efficiency of elimination of compounds in several municipal wastewater treatment plants (WWTPs).

Purpose: Introducing and developing new kinds of adsorbents are always a significant challenge in water treatments. In this work, for the first time, graphene oxide (GO), nitrogen-doped graphene oxide (ND-GO), highly nitrogen-doped graphene oxide (HND-GO), and 3D high nitrogen-doped graphene oxide (3D-HND-GO) were synthesized and comparatively evaluated in the removal of nitrate content of tap and underground waters. Methods: The removal of the target analyte was performed through a batch adsorption approach, and the factors influencing its removal efficiency (i.e., initial pH of the sample, primary concentrations of nitrate, amount of adsorbent, and contact time) were evaluated through a central composite design (CCD) and response surface methodology (RSM). Results: Based on the results, 3D-HND-GO showed the highest removal efficiency in comparison with the other mentioned nanoparticles. The nitrate removal using this adsorbent was modeled successfully so that R2, adjusted R2, and predicted R2 values were 0.9717, 0.9508, and 0.9010, respectively. In addition, the optimal removal condition was achieved using the Nelder-Mead non-linear optimization algorithm as follow: the initial concentrations of nitrate (expressed as nitrogen): 15.0 mg/mL, the amount of the adsorbent: 2.0 mg/mL; pH of the sample: 3.0; and the contact time: 20.0 min. Under this optimal condition, the actual removal result (92.5 ± 4.0%) was in good agreement with the expected value (94.8 ± 5.1%). Additional studies were also performed to comprehensibly evaluate the adsorption activity of the adsorbent (e.g., kinetic, isotherm, and desorption parameters). The adsorption isotherm complied with the Langmuir model illustrating the considerable mono-layer adsorption capacities for the target ions with qm of 8.7 mg/g. The adsorption process was indicated to obey a pseudo 2nd order kinetic model, with the rate-limiting step for the adsorption phase. Conclusions: This study revealed which 3D-HND-G leads to improved yield in the nitrate ions elimination, particularly at acidic media, which was related to the enhanced dispersibility and larger surface area. The adsorbent was further successfully used for treating tap and underground water samples. At the present moment, research as grown to modify 3D-HND-G in orders to increase the potentiality for industrial applications. [ABSTRACT FROM AUTHOR]

Functional microorganisms play a vital role in removing environmental pollutants because of their diverse metabolic capability. Herein, a function-oriented fluorescence resonance energy transfer (FRET)-based graphene quantum dots (GQDs-M) probe was developed for the specific identification and accurate sorting of azo-degrading functional bacteria in the original location of environmental samples for large-scale culturing. First, nitrogen-doped GQDs (GQDs-N) were synthesized using a bottom-up strategy. Then, a GQDs-M probe was synthesized based on bonding FRET-based GQDs-N to an azo dye, methyl red, and the quenched fluorescence was recovered upon cleavage of the azo bond. Bioimaging confirmed the specific recognition capability of GQDs-M upon incubation with the target bacteria or environmental samples. It is suggested that the estimation of environmental functional microbial populations based on bioimaging will be a new method for rapid preliminary assessment of environmental pollution levels. In combination with a visual single-cell sorter, the target bacteria in the environmental samples could be intuitively screened at the single-cell level in 17 bacterial strains, including the positive control Shewanella decolorationis S12, and were isolated from environmental samples. All of these showed an azo degradation function, indicating the high accuracy of the single-cell sorting strategy using the GQDs-M. Furthermore, among the bacteria isolated, two strains of Bacillus pacificus and Bacillus wiedmannii showed double and triple degradation efficiency for methyl red compared to the positive control (strain S12). This strategy will have good application prospects for finding new species or high-activity species of specific functional bacteria. [ABSTRACT FROM AUTHOR]

Antibiotic resistance of bio-threat agents holds major concerns especially in light of advances in methods for engineering pathogens with antibiotic resistance. Preparedness means for rapid identification and prompt proper medical treatment are of need to contain the event and prevent morbidity and spreading of the disease by properly treating exposed individuals before symptoms appearance. Herein, we describe a novel, rapid, simple, specific, and sensitive method named Micro-Agar-PCR-test (MAPt), which determines antibiotic susceptibility of bio-terror pathogens, directly from environmental samples, with no need for any prior isolation, quantification, or enrichment steps. As proof of concept, we have used this approach to obtain correct therapeutic antibiotic minimal inhibitory concentration (MIC) values for the Tier-1 select agents, Bacillus anthracis , Yersinia pestis , and Francisella tularensis , spiked in various environmental samples recapitulating potential bioterror scenarios. The method demonstrated efficiency for a broad dynamic range of bacterial concentrations, both for fast-growing as well as slow-growing bacteria and most importantly significantly shortening the time for accurate results from days to a few hours. The MAPt allows us to address bioterror agents-contaminated environmental samples, offering rational targeted prophylactic treatment, before the onset of morbidity in exposed individuals. Hence, MAPt is expected to provide data for decision-making personal for treatment regimens before the onset of symptoms in infected individuals. [ABSTRACT FROM AUTHOR]

In the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application of molecularly imprinted polymers (MIPs) is gaining greater popularity. It is mainly related to their physicochemical properties, sorption capacity and selectivity, thermo-mechanical resistance, as well as a wide range of polymerization techniques allowing to obtain the desired type of sorption materials, adequate to a specific type of pesticide. This paper targets to summarize the most popular and innovative strategies since 2010, associated with the MIPs synthesis and analytical procedures for pesticides determination in environmental and food samples. Application of multi-criteria decision analysis (MCDA) allows for visualization of the most beneficial analytical procedures in case of changing the priority of each step of analysis (MIPs synthesis, sample preparation process—pesticides extraction, chromatographic analysis) bearing in mind metrological and environmental issues.