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Electrophoresis Mar 2021Arsenic aromatic compounds including p-arsanylic acid (pASA) are still widely used in a number of countries as the feed additives in animal breeding resulting in its...
Arsenic aromatic compounds including p-arsanylic acid (pASA) are still widely used in a number of countries as the feed additives in animal breeding resulting in its entering the environment. Under the influence of oxidizing agents or UV radiation, pASA undergoes transformations leading to generation of inorganic arsenic species that are more mobile and toxic than organic ones. On the one hand, an approach based on the treatment of contaminated waters by UV irradiation seems perspective for their detoxification, but the feasibility of this approach depends on the composition of the products forming as a result of photodegradation. In the present work, a CZE was applied for the study of the pASA degradation process during stationary (308 nm) photolysis in the presence of Fe(III)-oxalate complex. A developed assay allowed controlling the parent compounds and also As-containing products of pASA degradation, presented mainly by arsenate and arsenite ions. It was found that the main inorganic derivatives of the pASA photolytic conversions are presented by arsenate and arsenite ions whose ratio depends on the initial amount of pASA and reaction conditions.
Topics: Animals; Arsanilic Acid; Arsenates; Arsenic; Arsenites; Electrophoresis, Capillary; Ferric Compounds; Hydrogen-Ion Concentration; Organic Chemicals; Photolysis
PubMed: 33185273
DOI: 10.1002/elps.202000262 -
Food Chemistry Jun 2021The novel molecularly imprinted microspheres for four phenylarsonic compounds have been firstly prepared with the reversible addition-fragmentation chain transfer...
The novel molecularly imprinted microspheres for four phenylarsonic compounds have been firstly prepared with the reversible addition-fragmentation chain transfer polymerization in a suspension system. The resulting polymeric microspheres were characterized by infrared spectrum, scanning electron microscope and differential scanning calorimetry. With serial adsorption experiments, the polymeric microspheres showed highly specific molecular recognition, fast mass transfer rate and robust adsorption of the substrates. Then, the imprinted polymer was used as the solid-phase extraction adsorbent to extract the phenylarsonic compounds from the feeds, edible chicken and pork. The cartridge was washed with 2 mL ethyl acetate and eluted with 3 mL of methanol- acetic acid (90:10, v/v). The recoveries of the molecularly imprinted solid-phase extraction (MISPE) column ranged from 83.4% to 95.1%. This work provided a versatile approach for the specific extraction of the organoarsenic compounds from complicated matrices and exhibited a bright future for the application of MISPE column.
Topics: Adsorption; Animal Feed; Animals; Arsanilic Acid; Arsenicals; Chickens; Chromatography, High Pressure Liquid; Meat; Molecular Imprinting; Muscles; Polymers; Roxarsone; Solid Phase Extraction; Swine
PubMed: 33484954
DOI: 10.1016/j.foodchem.2021.129054 -
Journal of Hazardous Materials Feb 2024Aromatic organoarsenic feed additives have been extensively used in poultry and livestock farming; however, a risk of releasing toxic inorganic arsenic exists when they...
Aromatic organoarsenic feed additives have been extensively used in poultry and livestock farming; however, a risk of releasing toxic inorganic arsenic exists when they are exposed to the environment. An in-depth understanding of the adsorption -migration behavior of aromatic organoarsenicals on environmental media is limited. In this study, p-arsanilic acid (p-ASA) and roxarsone (ROX) were considered as examples to systematically study their adsorption behaviors on the surface of hematite, a representative iron oxide in soil. By comparing the adsorption abilities and adsorption kinetics of hematite exposed with different facets (hexagonal nanoplates, HNPs, mainly exposed with {001} facets and hexagonal nanocubes, HNCs, exposed with {012} facets), combined with in situ shell-isolated nanoparticle enhanced Raman spectroscopy characterization and density functional theory simulation, the facet-dependent adsorption performance was observed and the mechanism revealed. The results showed that p-ASA formed a bidentate binuclear complex on HNCs and HNPs, whereas ROX formed monodentate mononuclear and bidentate binuclear configurations on the {001} and {012} facets, respectively. These differences not only lead to facet-dependent adsorption capacities but also affect their stability, as verified by sequential extraction experiments, affecting the environmental behavior and fate of aromatic organoarsenicals. This study not only provides insights into the environmental behavior of aromatic organoarsenicals but also offers theoretical support for the development of functional adsorbents and remediation strategies.
PubMed: 37976861
DOI: 10.1016/j.jhazmat.2023.132976 -
The Science of the Total Environment Nov 2020In this study, resin-based hydrated iron oxide (HFOR) composites were prepared and used as a functional adsorbent for the simultaneous removal of p-Arsanilic acid...
In this study, resin-based hydrated iron oxide (HFOR) composites were prepared and used as a functional adsorbent for the simultaneous removal of p-Arsanilic acid (p-ASA) and arsenate (As (V)). The effects of solution pH and coexisting substances on the adsorption of different arsenic species were also investigated. Results showed that the coexisting substances slightly affected the adsorption process of two arsenic species. Analysis of the adsorption behavior, isotherm equilibrium, and adsorption kinetics, as well as that results of the X-ray photoelectron spectroscopy, zeta potential, and other analytical methods revealed that the satisfactory adsorption performance of HFOR can be attributed to the electrostatic interactions induced by the positively charged groups and the coordination of the hydrated iron oxide nanoparticles, which exhibited excellent specific adsorption for both arsenic species. Moreover, HFOR showed high acid and alkali resistance and reusability, as well as a constant co-removal performance for different arsenic species in five consecutive operating cycles (55 mg As/g of As(V) and 18 mg/g of p-ASA). Results of continuous running fixed-bed column experiments confirmed that HFOR enabled excellent simultaneous adsorption for p-ASA and As(V).
PubMed: 32629256
DOI: 10.1016/j.scitotenv.2020.140508 -
Langmuir : the ACS Journal of Surfaces... Sep 2020Reported here is a new chemical route for the wet chemical functionalization of germanium (Ge), whereby arsanilic acid is covalently bound to a chlorine (Cl)-terminated...
Reported here is a new chemical route for the wet chemical functionalization of germanium (Ge), whereby arsanilic acid is covalently bound to a chlorine (Cl)-terminated surface. This new route is used to deliver high concentrations of arsenic (As) dopants to Ge, via monolayer doping (MLD). Doping, or the introduction of Group III or Group V impurity atoms into the crystal lattice of Group IV semiconductors, is essential to allow control over the electronic properties of the material to enable transistor devices to be switched on and off. MLD is a diffusion-based method for the introduction of these impurity atoms via surface-bound molecules, which offers a nondestructive alternative to ion implantation, the current industry doping standard, making it suitable for sub-10 nm structures. Ge, given its higher carrier mobilities, is a leading candidate to replace Si as the channel material in future devices. Combining the new chemical route with the existing MLD process yields active carrier concentrations of dopants (>1 × 10 atoms/cm) that rival those of ion implantation. It is shown that the dose of dopant delivered to Ge is also controllable by changing the size of the precursor molecule. X-ray photoelectron spectroscopy (XPS) data and density functional theory (DFT) calculations support the formation of a covalent bond between the arsanilic acid and the Cl-terminated Ge surface. Atomic force microscopy (AFM) indicates that the integrity of the surface is maintained throughout the chemical procedure, and electrochemical capacitance voltage (ECV) data shows a carrier concentration of 1.9 × 10 atoms/cm corroborated by sheet resistance measurements.
PubMed: 32787047
DOI: 10.1021/acs.langmuir.0c00408 -
Journal of Colloid and Interface Science Oct 2019Arsenic species are regarded as typical water pollutants due to their toxicity. The chemical structures of arsenic species greatly influence their migration and...
Arsenic species are regarded as typical water pollutants due to their toxicity. The chemical structures of arsenic species greatly influence their migration and transformation in the environment. Metal-organic frameworks (MOFs) are used as reliable adsorbents to control arsenic contamination, so it is urgently needed to study the effect of chemical structure of arsenic species during adsorption process. The adsorption behaviors of arsenate (As(V)) and its organic forms such as roxarsone (ROX), p-arsanilic acid (p-ASA) and dimethyl arsenate (DMA) by MIL-101(Fe), a type of highly porosity iron-based MOFs in aqueous environment were detailed investigated. The adsorption kinetics of those arsenic species on MIL-101(Fe) is rapid followed with pseudo-second-order kinetic model. MIL-101(Fe) exhibits excellent adsorption capacities for As(V), ROX, p-ASA and DMA with maximum adsorption capacities of 232.98, 507.97, 379.65 and 158.94 mg g, respectively. The formed FeOAs inner-sphere coordination between arsenic species and the incomplete-coordinated cationic Fe in the MIL-101(Fe) cluster is the primary adsorption mechanism based on FTIR and XPS analysis. Substituent aromatic units in ROX and p-ASA strengthen the adsorption on MIL-101(Fe) through hydrogen bonds and π-π stacking interaction, resulting in higher adsorption capacities far beyond that of As(V) and DMA. The reusability of MIL-101(Fe) is limited by the strong FeOAs coordination. These results confirm MIL-101(Fe) a reliable adsorbent to control the aqueous arsenic species contamination and emphasize the significant role of the chemical structure of arsenic speciation on adsorption performances of MOFs.
PubMed: 31352244
DOI: 10.1016/j.jcis.2019.07.046 -
Environmental Science and Pollution... Apr 2020Given their considerable solubility in water and potentially high toxicity to human health, organoarsenic compounds have become an emerging contaminant. Herein, a...
Given their considerable solubility in water and potentially high toxicity to human health, organoarsenic compounds have become an emerging contaminant. Herein, a heterogeneous Fenton process mediated by SiO-coated nano zero-valent iron (SiO-nZVI) was employed to simultaneously remove the p-arsanilic acid (p-ASA, a typical organoarsenic compound) and the released arsenic. The initial pH value significantly influenced on the degradation of p-ASA and at the optimal pH (3.0), p-ASA (10 mg L) could be completely oxidized to As(V), NH, and plentiful phenolic compounds such as phenol and p-hydroquinone via the cleavage of C-N and C-As bonds within 60 min in pure water. Meanwhile, although the formed lepidocrocite and magnetite on the surface of SiO-nZVI significantly limited the reutilization, they played a vital role in the adsorption of the released As(V) and the residual arsenic levels in the effluent were as low as 0.031 mg L, meeting both the drinking water standard of the World Health Organization (WHO) and the surface water standard of China (0.05 mg L). Furthermore, high-level dissolved organic matters (DOM) (> 2 mg C L) exhibited strong interference with both the oxidation of p-ASA and adsorption of arsenic, but the interference could be eliminated by increasing the SiO-nZVI dosage or adding HO. Importantly, this system could completely remediate p-ASA in a short time and simultaneously avoid the secondary pollution caused by inorganic arsenic, which was significant for the remediation of organoarsenic pollutants in swine wastewater.
Topics: Animals; Arsenic; China; Hydrogen Peroxide; Iron; Silicon Dioxide; Swine; Water Pollutants, Chemical
PubMed: 31983004
DOI: 10.1007/s11356-020-07808-2