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Benzotriazole ultraviolet stabilizers (BUVSs), used extensively in both consumer and industrial products, are emerging pollutants of concern, of which, 2-(3, 5-di- tert -amyl-2-hydroxyphenyl) benzotriazole (UV-328) is currently listed under the Stockholm Convention. BUVSs have been detected widely in environmental and biological matrices; thus, they are accessible to humans via environmental exposure and dietary intake. Due to their bioaccumulation and toxicity, the requirements for environmental human health risk assessment led to the development of sensitive analytical methods for BUVSs. In this review, the analytical methods for BUVSs and metabolites in environmental and biological samples are summarized, mainly focusing on pretreatment techniques including liquid extraction, solid-phase extraction and gel permeation chromatography, as well as instrumental analysis with chromatography-mass spectrometry. In addition, the overall occurrence of BUVSs in environmental matrices and organisms is summarized, to discuss possible human exposures. Finally, the metabolism, toxicity, and human health impacts of BUVSs are overviewed. [Display omitted] • GPC combined with SPE are the mostly used clean-up techniques for complex samples. • Trace BUVS analysis in environment is almost exclusively achieved by GC/MS or LC/MS. • BUVSs are extensively present in the environment and accumulated in organisms. • BUVSs can be metabolized by human CYP450 and mainly metabolized by the liver. • Endocrine disruption, liver toxicity, and immunotoxicity are highlighted. [ABSTRACT FROM AUTHOR]

Medium and heavy crude oils and high-boiling distillation fractions which are increasingly used in petroleum industry contain high concentrations of sulfur and metals. Their behavior in refining processes is critically dependent on the speciation. Recent analytical developments, especially on the level of coupled techniques and high-resolution mass spectrometry, start allowing the speciation of individual metal compounds in crude oil known for its extreme complexity. These developments include: (i) GC stationary phases of high thermal stability and the high-temperature interfaces with ICP-MS and TOF-MS; (ii) high-efficiency microcolumn gel-permeation chromatography with detection by sector-field ICP-MS; (iii) thin layer chromatography coupling with laser ablation ICP-MS detection; and (iv) two-dimensional separation protocols increasing the purity of heteroelement containing fractions. Progress in electrospray and atmospheric-pressure photoionization Fourier Transform MS allows resolutions of above 1,000,000 to be achieved making it possible to identify by accurate mass measurement individual sulfur and metal species directly in crude oils. [ABSTRACT FROM AUTHOR]

Emerging persistent organic pollutants (ePOPs) include polybrominated diphenyl ethers (PBDEs) and perfluorooctane sulfonyl fluoride/perfluorooctane sulfonate (POSF/PFOS), which are newly listed in the Stockholm Convention. Other ePOPs, which have not been regulated, include organophosphate flame retardants (PFRs), novel brominated flame retardants (NBFRs) and other perfluoroalkyl substances (PFASs). Often ePOPs data related to occurrence, toxicity, impact or environmental behavior are insufficient or inadequate because of the lack of proper analytical methods to obtain them. Thus, a critical review of the analytical procedures proposed in the last six years (2011–2017) for determining ePOPs by chromatographic methods in the different compartments of the aquatic ecosystems is presented. The overall analytical procedure, from sampling to final determination, is emphasized presenting recent developments in the extraction, pre-concentration, and instrumental detection needed for the accurate quantification of ePOPs in environmental samples. Finally, this review examines the basic challenges we face in order to anticipate future directions and urgent needs of this field. [ABSTRACT FROM AUTHOR]

In recent years, graphene-based magnetic composites have attracted tremendous research interest owing to its exceptional properties, such as huge surface area, large delocalized π-electron system, strong magnetic responsiveness, and excellent mechanical/thermal stability. These promising properties together with the ease of processibility and functionalization render graphene-based magnetic composites to be ideal adsorbents in magnetic solid-phase extraction. In this review, we outline the state of the art on the preparation approaches for different graphene-based magnetic composites and its application as adsorbents in preconcentrating organic compounds, biological macromolecules, and metal ions. In addition, future research directions of this type of magnetic materials are identified as well. [ABSTRACT FROM AUTHOR]

Pesticide residue analysis in olive oil presents difficulties due to the high amount of co-eluted compounds resulting in high matrix effect. Different extraction/clean-up methods including gel permeation chromatography, liquid/liquid extraction, solid-phase extraction and other extraction methods are applied to overcome these difficulties. Recent approaches such as the addition of the freezing-out step and the application of Enhanced Matrix Removal-Lipid sorbent (EMR-Lipid) are reported. Gas chromatography and liquid chromatography coupled to mass spectrometry are considered the gold standard technologies covering a wide scope of pesticides. This review recapitulates the methods most widely used for the determination of pesticide residues in vegetable oils. As a continuation of previous reviews, the work conducted is an update review of methods from 2006 in this field, evaluating their strengths and limitations. Main analytical parameters of the different extraction procedures and detection methods are discussed in terms of recoveries, robustness, limit of quantification, and matrix effect. [ABSTRACT FROM AUTHOR]

Polysaccharides with multiple biological activities and health benefit effects are usually considered as one of the major function components in food and medicine dual purposes Chinese herbs (FMDPCH). With the increasing interest in the utilization of FMDPCH, their quality control is very important for ensuring their safety and efficacy. To date, there is no report focus on the analysis of polysaccharides in FMDPCH. Herein, advanced development for quality control approaches, including sample preparation, separation and fraction, qualitative and quantitative analysis, of polysaccharides in MPDPCH were reviewed and discussed. Especially, discrimination and quantification of polysaccharides, respectively, based on novel saccharide mapping and universal refractive index increment were focused. Besides, the perspective for the characterization of polysaccharides has also been described. [ABSTRACT FROM AUTHOR]

Environmental health is systematically compromised by persistent toxic substances, which may have serious implications in terms of food safety issues and, thus, in general public health. In this context, polybrominated diphenyl ethers (PBDEs) and their biologically active metabolites have been increasingly assessed in seafood, the main route of human exposure. As a consequence, a multiplicity of solvent-assisted analytical approaches is now available to accurately determine tiny amounts of these contaminants in complex matrices, like seafood. However, the majority of analytical procedures lead to high organic solvent consumption, thereby also contributing to the deterioration of environmental health. The current review provides up-to-date information and critical discussion regarding the most common methodologies applied in the determination of PBDEs and their metabolites in seafood (2006–2016), from sample preparation to instrumental analysis. The ultimate goals of this comprehensive survey are to sensitize field researchers to work under the principles of green chemistry and to improve the global consciousness on the potential necessity of their regulation in foodstuffs. [ABSTRACT FROM AUTHOR]

Honey is a natural sweetening agent widely used in food products and as a daily diet ingredient, but it also has medicinal properties. An increase in the demand for honey has resulted in adulteration by different sugar syrups. Authentication is therefore important for consumer confidence. This comprehensive overview covers known syrup adulterants and the analytical methodologies adopted for their detection in honey. For instance, TLC is the oldest method for honey analysis. C-isotope methods such as SCIRA, which can differentiate adulterated honey from C3 plants, are explained. Common analytical techniques such as HPAEC, GC, and HPLC are discussed. Advanced techniques, including IR, NMR, and Raman spectroscopy, which enhance the analysis process for larger numbers of samples, are also presented. Finally, Q-TOF-MS is addressed as a metabolomics-based detection method, since it has recently gained momentum following the increase in different adulterants that make detection more difficult. [ABSTRACT FROM AUTHOR]

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. TBBPA and its alternative, tetrabromobisphenol S (TBBPS), are the reactive chemicals used to produce TBBPA/S derivatives. The manufacturing and application of TBBPA/S derivatives may result in their accumulation in environmental compartments and may cause risks to environmental safety and human health. To investigate the occurrence and transformation products of TBBPA/S and TBBPA/S derivatives, it is imperative to develop effective sample preparation and sensitive analytical methods for various environmental matrices. In this paper, we summarize the techniques for analysis of TBBPA/S and their derivatives. We also critically review methodologies for the identification of unknown metabolites transformed from these chemicals. In the perspective section, we discuss trends in analytical strategies for studying emerging TBBPA/S derivatives. [ABSTRACT FROM AUTHOR]

This review presents an overview of size-exclusion chromatographic separation and characterization of noble metal nanoparticles (NPs) and quantum dots (QDs) over the past 25 years. The properties of NPs and QDs that originate from quantum and surface effects are size dependent; to investigate these properties, a separation technique such as size-exclusion chromatography (SEC) is often needed to obtain narrow-distribution NP populations that are also separated from the unreacted starting materials. Information on the size distributions and optical properties of NPs has been obtained by coupling SEC to detection methods such as ultraviolet–visible and/or fluorescence spectroscopy. Problems associated with the sorption of NPs and QDs onto various SEC stationary phases, using both aqueous and organic eluents, are also discussed. [ABSTRACT FROM AUTHOR]

The separation of molecular compounds based on their capacity to access the intra-particle pore volume of chromatographic media, which is dictated by the relative size in solution of those compounds, has been commonly known as size-exclusion chromatography (SEC) or gel-permeation chromatography (GPC). Conventionally, these two terms have been applied to the analysis of biomolecules and polymers, respectively. Over the more than half-a-century history of size-based separations, there has been a series of advancements, starting from the earliest soft-gel particles and culminating within the past few years in the use of sub-2-µm particles in ultra-high-performance liquid chromatography (UHPLC). The intent of this review is to provide a concise synopsis of the advancements of both chromatography columns and instrumentation for protein and polymer size-based separations. Also, this review presents brief summaries of the application of UHPLC technology for these classes of analytes. [ABSTRACT FROM AUTHOR]

Abstract: The key factors for the success of matrix solid-phase dispersion (MSPD) are its feasibility, flexibility, versatility, low costs and rapidity. Furthermore, with MSPD, it is possible to perform, on a small sample aliquot, extraction and clean up in a single step. In recent years, the greatest innovation in the MSPD technique has been the employment of unusual supporting materials (i.e. highly selective molecularly-imprinted polymers and the less specific multi-walled carbon nanotubes), although traditional sorbent and supports are still widely employed. Another novelty is the growing application of the multivariate statistical approach (experimental design) to optimize the extraction conditions. The purpose of this review is to present a rapid overview of MSPD applied to specific matrices and an update on the latest trends and innovations in the field since 2009. We pay particular attention to unusual matrices, new rapid clean-up techniques, and comparison with other sample-preparation methods. [Copyright &y& Elsevier]

Abstract: This critical review reports on the up-to-date development designs of mesofilters for molecular sieving of macromolecules. Tight mesoporous silica nanotubes (NTs) provide a promising candidate as a filter for the size-exclusion separation of large quantities of macromolecules within a short period. First, we focus on the formation of the mesoporous structures inside anodic alumina membrane (AAM) using nanolinker approaches. Second, we discuss the systematic design of the robust mesofilters based on densely-engineered mesopores of silica NTs, which are vertically aligned with the open surfaces of top-bottom ends inside the AAM. Third, we present the bench-top filtration method as a powerful tool for the size-exclusion separation of macromolecules. Significantly, the evaluation of the intrinsic properties of mesofilters (e.g., diffusivity, separation efficiency, long-term stability, and reusability) compared them with commercial, mature membranes used for separation of macromolecules. [Copyright &y& Elsevier]

Steroid estrogens have been identified in the solid matrices of unit treatment processes in sewage treatment works (STWs) and in sediments of watercourses that receive effluent. This article discusses the sample preparation and analytical considerations necessary for reliable determination and the need to evaluate for possible matrix interferences during method development. Complementing this is a case study highlighting the potential for analyte transformation during sample preparation and the phenomena of ion suppression when utilising LC/MS ESI with a comparison of method recoveries by GC/MS. We discuss the use of LC/MS/MS and TOF instruments; however, at present, their use in environmental analyses appears to be limited because of their capital costs. [Copyright &y& Elsevier]

The last few decades have seen dramatic growth in the scale of production and use of brominated flame retardants (BFRs). Not surprisingly, the levels of these compounds in the environment have increased as well. Even though the acute toxicity of most BFRs seems to be fairly low, some have shown similar toxic effects to PCBs and polychlorinated dibenzo-p-dioxins and furans. Thus, BFRs are a potential hazard to the environment and their levels in the environment must be monitored. This article gives a brief overview of the analytical methodology used for the determination of BFRs in environmental samples and the levels of BFRs found in the samples. [Copyright &y& Elsevier]

More than 100 different arsenic species of diverse characteristics are present in the environment and biological systems. The identification and quantification of individual arsenic species are critical to understanding the distribution, environmental fate and behaviour, metabolism, and toxicity of arsenic. This review summarizes sample preparation, separation, detection, and method validation for arsenic speciation analysis. An emphasis is placed on chromatographic separation techniques, relating the physicochemical properties of arsenic species to their efficient separation. Anion exchange, cation exchange, reversed-phase, ion pair, and size exclusion chromatography are useful to separate various arsenic species. Recent research has explored hydrophilic interaction liquid chromatography (HILIC), multiple separation mechanisms, and testing of fluorophenyl and graphene oxide stationary phases for the separation of arsenic species. Sample preparation, extraction of arsenic species, recovery of arsenic species from separation columns, and method validation are discussed in light of their importance to the integrity and accuracy of speciation analysis. • Chromatography and mass spectrometry are complementary for speciation analysis. • Chromatography is critical for separation of arsenic species. • Diverse arsenic species require multiple modes of separation. • Sample preparation and extraction must maintain integrity of arsenic species. [ABSTRACT FROM AUTHOR]