Endocrine disrupting compounds and other emerging contaminants in the environment: a survey on new monitoring strategies and occurrence data

An overview of Toxicity Identification and Evaluation (TIE) procedures, used for the effect-based analysis of endocrine disrupting compounds (EDCs) in environmental samples, is presented. Future trends in advanced chemical analysis of EDCs and some emerging contaminants are outlined. The review also gives an overview of concentration levels found in environmental samples and discusses the correlation of calculated estrogenicity (based on chemical analysis of target EDCs) with that measured by various bioassays.     

Analytical methods for the determination of emerging organic contaminants in the atmosphere

Concerns over the occurrence and transport of emerging organic contaminants (EOCs) from local sources to remote regions have resulted in wide developments in sampling strategy and analytical methodology for the determination of trace concentrations of EOCs in the atmosphere. This article discusses developments in the determination of EOCs in ambient air which includes polyfluorinated alkyl substances (PFASs), brominated-flame retardants (BFRs), synthesis musk fragrances, and alkylphenols (APs). References were mainly summarized from the past 5 years (2002 up to present) on new developments of sampling methods, extraction, separation/fractionation and/or applications of new technologies for sampling and determination.     

Analytical procedures for the determination of emerging organic contaminants in plant material: A review

In this review, recent developments for the determination of emerging organic contaminants (EOCs) in plant tissues are discussed focusing on the homogenization, extraction and determination steps involved. Eleven classes of EOCs, namely antibiotics, analgesics, antiepileptics, antidepressants, antiseptics, plasticizers, fragrances, surfactants, flame retardants, and phenoxy acid herbicides, have been evaluated. Methods are critically reviewed in terms of all the analytical steps involved in the analysis, sampling and sample preparation, separation, and the detection strategies employed. The extraction from tissue samples was performed in most cases by solid–liquid extraction, whereas the clean-up was performed by solid-phase extraction. The identification and quantification of EOCs in crops from the agricultural field (i.e. parts per billion range) is usually performed by using mass spectrometry techniques such as single quadrupole mass spectrometry or tandem mass spectrometry coupled to high resolution chromatographic techniques. Enzyme-linked immunosorbent assays are more rarely used. New developments such as in vivo solid-phase microextraction (SPME) and the assessment of the bioavailability–bioaccesibility of contaminants in crops are shown. The main scope of this review is to critically evaluate the current state of the art of the analytical techniques used and to identify the research needs in the determination of EOCs in crops.     

Overview of nanosorbents used in solid phase extraction techniques for the monitoring of emerging organic contaminants in water and wastewater samples

In this article, we have critically overviewed some interesting articles published in 2015–2019 about the use of the nanosorbents for the extraction of emerging organic contaminants (EOCs) from various environmental samples. Properties, advantages, disadvantages, and the applicability of different categories of nanosorbents used for the extraction of EOCs are evaluated and discussed. The potential applications of these nanomaterials as adsorptive phase in solid-phase extraction (SPE) based techniques are reviewed.     

Multiresidue method for the analysis of emerging contaminants in wastewater by ultra performance liquid chromatography-time-of-flight mass spectrometry

A multiresidue method for screening of emerging contaminants in aquatic environments was developed. The method was based on sample pretreatment with solid phase extraction (SPE) and analysis with an ultra performance liquid chromatograph-time-of-flight mass spectrometer (UPLC-TOF-MS). The method was optimized and tested with standard solutions of model compounds containing 84 pesticides and pharmaceuticals. Four different SPE sorbents were evaluated to gain maximum recovery for the analytes. For the final procedure a combination of two different sorbents was chosen. In spite of high matrix suppression, the method quantification limits (MQLs) were acceptable. Therefore, the method can be used for screening known target compounds. The applicability of the method for posttarget and nontarget screening will be reported later. To preliminarily assess the quantitative performance of the method, some compounds in wastewater effluent were quantified using the standard addition method. Three pesticides and eight pharmaceuticals were found in concentrations up to ～2200 ng/L.     

Liquid chromatography-(tandem) mass spectrometry of selected emerging pollutants (steroid sex hormones,drugs and alkylphenolic surfactants) in the aquatic environment

Among the various compounds considered as emerging pollutants, alkylphenolic surfactants, steroid sex hormones, and pharmaceuticals are of particular concern, both because of the volume of these substances used and because of their activity as endocrine disruptors or as causative agents of bacterial resistance, as is the case of antibiotics. Today, the technique of choice for analysis of these groups of substances is liquid-chromatography coupled to mass spectrometry (LC–MS) and tandem mass spectrometry (LC–MS–MS). In the last decades, this technique has experienced an impressive progress that has made possible the analysis of many environmental pollutants in a faster, more convenient, and more sensitive way, and, in some cases, the analysis of compounds that could not be determined before. This article reviews the LC–MS and LC–MS–MS methods published so far for the determination of alkylphenolic surfactants, steroid sex hormones and drugs in the aquatic environment. Practical considerations with regards to the analysis of these groups of substances by using different mass spectrometers (single quadrupole, ion trap and triple quadrupole instruments, etc.), interfaces and ionization and monitoring modes, are presented. Sample preparation aspects, with special focus on the application of advanced techniques, such as immunosorbents, restricted access materials and molecular imprinted materials, for extraction/purification of aquatic environmental samples and extracts are also discussed.     

Photocatalysed degradation of uracil in aqueous titanium dioxide suspensions: mechanisms, pH and cadmium chloride effects

Upon UV irradiation, in O₂ saturated aqueous titanium dioxide suspensions, uracil is almost completely mineralised. Most of the organic compounds occurring during the photodegradation process have been identified by means of liquid chromatography and mass spectrometry coupled techniques (LC–MS). The first step of the mineralisation leads to the formation of uracilglycol. Then, the main products generated during the photodegradation exhibit new functions such as polyol, carboxylic and aldehyde. The presence of urea has been clearly evidenced. At the end of the process, the ultimate step is the formation of nitrate and ammonium ions. The formation kinetics of intermediate products are modified by pH variation and CdCl₂ addition.     

Microwave-assisted extraction: Application to the determination of emerging pollutants in solid samples

Flame retardants, surfactants, pharmaceutical and personal care products, among other compounds, have been the object of numerous environmental studies. In this chapter, the application of microwave-assisted extraction (MAE) in the development of analytical methods for several groups of organic compounds with growing concern as emerging pollutants has been considered. Compared to other extraction techniques, optimization of MAE experimental conditions is rather easy owing to the low number of influential parameters (i.e. matrix moisture, nature of the solvent, time, power, and temperature in closed vessels). The great reduction in the extraction time and solvent consumption, as well as the possibility of performing multiple extractions, increasing the sample throughput, can also be highlighted among MAE advantages. In summary, the study of several applications of MAE to environmental problems demonstrates that this technique constitutes a good alternative for the determination of organic compounds in environmental samples. It can be used as a rapid screening tool, and also to obtain detailed information on the sources, behaviour and fate of emerging pollutants in environmental matrices.     

Accurate mass screening and identification of emerging contaminants in environmental samples by liquid chromatography-hybrid linear ion trap Orbitrap mass spectrometry

The European Reach legislation will possibly drive producers to develop newly designed chemicals that will be less persistent, bioaccumulative or toxic. If this innovation leads to an increased use of more hydrophilic chemicals it may result in higher mobilities of chemicals in the aqueous environment. As a result, the drinking water companies may face stronger demands on removal processes as the hydrophilic compounds inherently are more difficult to remove. Monitoring efforts will also experience a shift in focus to more water-soluble compounds. Screening source waters on the presence of (emerging) contaminants is an essential step in the control of the water cycle from source to tap water. In this article, some of our experiences are presented with the hybrid linear ion trap (LTQ) FT Orbitrap mass spectrometer, in the area of chemical water analysis. A two-pronged strategy in mass spectrometric research was employed: (i) exploring effluent, surface, ground- and drinking-water samples searching for accurate masses corresponding to target compounds (and their product ions) known from, e.g. priority lists or the scientific literature and (ii) full-scan screening of water samples in search of 'unknown' or unexpected masses, followed by MS(n) experiments to elucidate the structure of the unknowns. Applications of both approaches to emerging water contaminants are presented and discussed. Results are presented for target analysis search for pharmaceuticals, benzotriazoles, illicit drugs and for the identification of unknown compounds in a groundwater sample and in a polar extract of a landfill soil sample (a toxicity identification evaluation bioassay sample). The applications of accurate mass screening and identification described in this article demonstrate that the LC-LTQ FT Orbitrap MS is well equipped to meet the challenges posed by newly emerging polar contaminants.     

Microplastics in Mediterranean coastal area: toxicity and impact for the environment and human health

The so-called marine litter, and in particular microplastics (MPs) and nanoplastics (NPs), are ubiquitously distributed and recognised as an emerging risk for the environment and human health. It is known that marine environments are one of the most impacted areas and among them; coastal zones are the most contaminated ones. They are subjected to population pressure, tourism, harbours, desalination plants, marine traffic and fish farms.This review is focused on the Mediterranean Sea, currently considered one hot spot of microplastics pollution in the world, as a consequence of the high number of plastic marine litter generating activities and its characteristic morphology of semi-enclosed sea. MPs and NPs have been detected not only in surface water and water columns but also in sediments, deep seafloor, and biota including fish and seafood for human consumption. Because of this, different European legislation initiatives have been launched during the last years in order to prevent MPs and NPs contamination and to face derived problems. Finally, this review summarises the main problems and shortcomings associated to MPs and NPs analyses such as their identification and quantification or the necessity of standardised protocols.     

Trends in the monitoring of legacy and emerging organic pollutants in protected areas

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.     

Accumulation of selected metals in the fruits of medicinal plants grown in urban environment of Islamabad,Pakistan

The present study is based on the measurement of selected metals (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb, Sr and Zn) in the fruits of eight medicinal plants (Carrisa opeca, Phyllanthus emblica, Solanum nigrum, Zizyphus nummularia, Zizyphus mauritiana, Physalis minima, Opuntia dillenii and Phoenix dactylifera) and relevant soil samples by atomic absorption spectrometry. Highest average concentrations of Cu (14.4 mg/kg), Cr (19.0 mg/kg), and Zn (125 mg/kg) were found in the fruits of P. minima, C. opeca and Z. nummularia, respectively, while O. dillenii showed the elevated mean levels of Cd (3.49 mg/kg), Sr (61.4 mg/kg), Mg (0.21%), Ca (6.62%) and Mn (44.6 mg/kg). However, highest average levels of Pb (41.7 mg/kg) and Co (38.4 mg/kg) were found in Z. mauritiana. Overall, most of the fruit samples showed higher contributions of Ca and Mg, followed by Fe, Zn, Co and Pb. In the case of soil samples, highest concentration was observed for Ca, followed by Fe, Mg, Mn and Sr, while lowest concentration was shown by Cd. Bioaccumulation factors exhibited significantly higher accumulation of Co (0.813–1.829) and Pb (0.060–2.350) from the soil to the fruits. Principal component analysis revealed significant anthropogenic contributions of Pb, Fe and Co in the fruit samples. Contamination factors and enrichment factors of Cd and Pb in the soil indicated very high contamination and extreme enrichment of these metals.     

微塑料介导重金属在陆生植物中迁移及生物效应的影响

随着地膜在现代化农业中的广泛应用,微塑料在土壤中的残留问题日益严重。环境中释放的微塑料可能会与先前存在的重金属相互作用,导致生物效应(生物积累/毒性),并对人类健康和农产品安全构成威胁。目前,大多数研究集中于单一影响因素在土壤系统中的暴露和转化分析,有关微塑料和共存金属对环境联合影响的相当有限。本文综述了微塑料与重金属来源、相互作用机理与影响因素的研究现状,阐述了陆生植物对二者联合污染的生理响应。此外,未来的研究还应重点探讨微塑料与重金属共同在植物上暴露的具体分子机制、通过食物链对人类健康的影响、与其他混合污染物联合作用及微塑料老化过程对重金属迁移动态变化过程的影响。     

水环境中微塑料的样品采集与分析进展

微塑料在环境中难以降解,可在水体、沉积物等环境介质中长期存在,并在水生生物体内积累,成为人们高度关注的环境问题之一。有关水环境中微塑料的污染研究尚处于起步阶段,快速、高效、准确的检测技术是水环境中微塑料研究的重要环节,对于优化研究路线、分析研究结果、总结微塑料污染规律至关重要。本文结合国内外微塑料污染研究进展,介绍了微塑料污染现状,并通过对环境样品中微塑料的采样、预处理以及定性定量分析方法的系统比较,总结了现行各种检测方法的优缺点及各自应用范围,最后指出了进一步研究的方向。     

Melt crystallized polyamide 6.6 and its copolymers, Part II. Crystallization mechanisms in the homopolymer

The crystallization kinetics of polyamide 66 have been studied using polarized optical microscopy. The growth rate data for positively birefringent spherulites in polyamide 66 show a distinct change of slope, which would be identified as a regime I/II transition based on secondary nucleation theory. However, recent data for the same specimens crystallized isothermally, from small angle X-ray scattering found the lamellar thickness to be constant at approximately 2.0 chemical repeat units, but with an internal crystalline core and a substantial innerlayer. The crystal core increases in size to 2 chemical repeat units with both time and temperature at the expense of the inner layer. This evidence is totally inconsistent with secondary nucleation theory, where a lamellar thickness which varies significantly with supercooling is an integral part of the derivations.A calculation of the dimensions of the critical nucleus is reported here, using surface free energies, which found it to be impossibly large at a value between 14 and 360 stems in size, further suggesting that another crystallization mechanism is operating. Calculations of the surface free energy of the hydrogen-bonded surface suggest that it is the high energy surface, rather than the folded surface, which normally occurs as the high energy surface in polymers. As the high energy surface, the hydrogen-bonded surface would be expected to be the growth face, as occurs in non-polymeric materials. An earlier model of Lovinger, which placed the fold direction into the melt, generating a rough surface, is consistent with these results.It is suggested that crystallization in polyamide 66, if not in all polyamides, occurs through a surface roughening mode of growth. This is a natural consequence of the presence of H-bonding in the direction of growth. In one sense, polyamide 66 is conventional in its growth behavior, relative to non-polymeric materials, as the growth face is the highest energy surface. As such, the lamellar thickness would no longer be a morphological variable related to the supercooling in any direct way as an essential part of any crystallization theory for polymers. Such behavior is impossible in other polymeric systems as the fold surface is the highest energy surface and the presence of folds prohibits growth on that surface. However, models of surface roughening, which were developed as an alternative explanation for the behavior of, principally, polyethylene, predict the conventional lamellar thickness - supercooling relation to exist, which is inconsistent with the observed existence of a constant lamellar thickness with variable crystal core dimensions.It is suggested that polyamide 66 be taken as a paradigm for a different kind of polymer crystallization than that normally encountered. That is crystallization in which the growth face is the highest energy surface, not the folded chain surface, having much in common with the behavior of non-polymeric materials. The energetic changes occurring in this case, however, are governed by a combination of entropic and enthalpic barriers to crystallization, rather than being dominated by enthalpic considerations, as in metals. This is a direct result of the entropic effects of the long chain nature of polymers combined with the enthalpic effects of the hydrogen-bonding.     

Advances in aptameric biosensors designed to detect toxic contaminants from food,water, human fluids,and the environment

Detection of toxic small molecule contaminants with sensitivity, accuracy, and specificity is a challenging task. Traditionally used HPLC and mass spectrometry-based assays suffer from several drawbacks, including lengthy sample preparation, heavy instrumentation, and the need for expert technicians. Specific, measurable, accurate, robust, and time-saving (SMART) biosensors are needed to detect toxic substances. Aptamers provide unique opportunities for the rapid development of SMART biosensors to meet above challenges. Since aptamers are short nucleotide sequences; they are easy for chemical synthesis and functional modifications. Aptamers acquire specific molecule recognition potential through unique chemical bonding, including H-bonds, pi-pi, van der Waals, and hydrophobic interactions. For the discovery of aptamers, the SELEX process is used. Recently, efforts have been made to develop aptamers to detect toxic small molecules like antibiotics, pesticides, insecticides, pollutants, toxins, and allergens. Aptamer technology is a promising tool for analyzing these chemicals from diverse matrices. This review provides an update on advances in nucleic acid-based aptameric sensors for molecular diagnostics of toxic chemical from food, water, human fluids, and the environment.     

Changes in induced polarization associated with the sorption of sodium, lead, and zinc on silica sands

Low-frequency dielectric spectroscopy can be measured in terms of a conductance and a phase lag between the electrical current and the electrical field. This conductance and phase lag can be written as into a complex conductivity with both an in-phase and quadrature components that are frequency dependent. In sands, the low-frequency (10 mHz-40 kHz) spectra of the complex conductivity are dominated by the polarization of the electrical double layer (especially the internal part of the electrical double layer called the Stern layer) and the Maxwell-Wagner polarization (typically above 100 Hz). We present a polarization that is able to explain the complex conductivity spectra including the grain size distribution, the porosity, and the complexation of the mineral surface with the ions of the pore water. To test this model, we investigate the sorption of various cations (Na, Pb, Zn) characterized by different affinities with the surface of silica. Sand column experiments were carried out to see the change in the complex conductivity during the advective/dispersive transport of a lead nitrate solution and a zinc sulfate solution, replacing a sodium chloride solution in the pore space of the sand. The complex conductivity model is able to explain the change of the phase over time.     

Combined method of solid-phase extraction and GC-MS for determination of acidic,neutral, and basic emerging contaminants in wastewater (Poland)

In this study an analytical procedure of solid-phase extraction (SPE) followed by gas chromatography mass spectrometry (GC-MS) was elaborated and validated for simultaneous determination of 11 acidic, neutral and basic emerging contaminants in wastewater. The most frequently used pharmaceuticals were studied, i.e. five anti-inflammatory drugs – ibuprofen, diclofenac, ketoprofen, naproxen and salicylic acid, an antiepileptic drug carbamazepine, clofibric acid, antibacterial triclosan, a plasticiser bisphenol A and two β-blockers – propranolol and metoprolol. Sample enrichment was performed using Oasis HLB sorbent. Sample pH and sorbent washing step during the solid-phase extraction were optimised on real wastewater samples. Recoveries of the most polar acidic compounds diminished substantially when the alkalinity of the sample loaded into the cartridge increased. Thus finally wastewater was extracted at pH 2.0. Before elution, sorbent was washed subsequently with 5% methanol in water and n-hexane, which resulted in best recoveries of most of the target compounds and reduced a co-elution phenomena with respect to β-blockers. The optimised method was successfully applied to influent and effluent samples from wastewater treatment plant, Krakow, Poland. All target compounds except propranolol were identified in wastewater at a concentration up to 12.8 µg L^?1.