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It would be of significance to design agreen composite for highly efficient uptake of contaminants. In this study, we fabricated an environmental friendly composite via insitu deposition of positively charged layered double hydroxide (LDH) on the surface of the negatively charged diatomite for efficient uptake of dye pollutants from aqueous solutions. The resulting LDH/diatomite (LDH/DIA) composites were characterised by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX), and N2 adsorption–desorption technique. The uptake performances of the resulting LDH/DIA composites were evaluated for the uptake of anionic tartrazine (TR) and erythrosine (ER) dyes. The uptake test of dyes was performed at ambient temperature by dispersing 10mg of the LDH/DIA in 10mL of dye solutions at pH 8 and 6 for TA and ER, respectively. The results show that composite can rapidly reduce the concentration of dyes in aqueous solutions from 20mg L−1 to 0.0001mg L−1. In addition, the uptake behaviour of this new adsorbent fits well with the Freundlich isotherm and the pseudo-second-order kinetic model. Langmuir isotherm study showed that the maximum uptake capacities of TR and ER dyes over the LDH/DIA composite were 555.6 and 625.2mg g−1, respectively, which were much higher than those of the known adsorbents. Our results suggested that the LDH/DIA has great potential applications as environmentally friendly materials for the treatment of wastewater with high concentration of anionic dyes. [ABSTRACT FROM AUTHOR]

Here is synthesized low‐cost and green core‐shell ZSM‐5 zeolite@ layered double hydroxides (ZSM‐5@LDH) via a simple in situ coprecipitation method. The structure of the sorbent was investigated using X‐ray diffraction, scanning electron microscopy, Fourier transforms infrared, Brunauer–Emmett–Teller, Barret‐Joyner‐Halenderm, and transmission electron microscope. The ZSM‐5@LDH was used for the removal of heavy metal ions include Pb(II), Zn(II), Cd(II), and Cu(II) and oxyanions include As(V), Cr(VI), Se(VI) from aqueous solutions. Synthesized sorbent showed selectivity for removing Pb(II) and As(V) ions. The kinetics models (pseudo‐first‐order and the pseudo‐second‐order models) and adsorption isotherms models (Langmuir and Freundlich models) of sorbent were studied to evaluate the performance of their practical application. The ZSM‐5@LDH for removal of Pb(II) and As(V) exhibits a high adsorption capacity (546.25 and 411.41 mg g−1, respectively) and very high distribution coefficient (Kd) values (4.07× 104 and 8.0 × 106 ml g−1, respectively), which place it at the top of materials known for the removal of Pb(II) and As(V). As a result, this study indicates that the ZSM‐5@LDH may be an ideal material for the selective removal of Pb(II) and As(V). [ABSTRACT FROM AUTHOR]

This research is an application of fiber‐in‐tube solid‐phase microextraction followed by high‐performance liquid chromatography with UV detection for the extraction and determination of trace amounts of bisphenol A. Nanomagnetic Fe3O4 was formed on the surface of polypropylene porous hollow fibers to increase the surface area and then it was coated with polystyrene. The introduction of polystyrene improves the surface hydrophobicity and is an appropriate extractive phase because it is highly stable in aquatic media. The extraction was carried out in a short capillary packed longitudinally with the fine fibers as the extraction medium. Extraction conditions, including extraction and desorption flow rates, extraction time, pH, and ionic strength of the sample solution, were investigated and optimized. Under optimal conditions, the limit of detection was 0.01 µg/L. This method showed good linearity for bisphenol A in the range of 0.033–1000 µg/L, with the coefficient of determination of 0.9984. The inter‐ and intraday precisions (RSD%, n = 3) were 7.9 and 6.3%, respectively. Finally, the method was applied to analysis of the analyte in thermal papers, disposable plastic cups, and soft drink bottles. [ABSTRACT FROM AUTHOR]

A novel plate‐like nano‐sorbent based on copper/cobalt/chromium layered double hydroxide was synthesized by a simple coprecipitation method. The synthesized nanoparticels were introduced into a stainless steel cartridge using a dry packing method. Then, the packed cartridge was introduced as a novel on‐line "packed in‐tube" configuration and followed by high performance liquid chromatography for the determination of trace amounts of ∆9‐tetrahydrocannabinol from biological samples and cannabis leaves. The as‐prepared sorbent exhibited long lifetime, good chemical stability, and high anion‐exchange capacity. Several important factors affecting the extraction efficiency, such as extraction and desorption times, pH of the sample solution and flow rates of the sample and eluent solutions, were investigated and optimized. Under optimized conditions, this method showed good linearity for ∆9‐tetrahydrocannabinol in the ranges of 0.09–500, 0.3–500, and 0.4–500 µg/L with coefficients of determination of 0.9999, 0.9991, and 0.9994 in water, serum and plasma samples, respectively. The inter‐ and intra‐assay precisions (n = 3) were respectively in the ranges of 1.8–4.6% and 1.9–4.0% at three concentration levels of 10, 50, and 100 µg/L. The limits of detection were also in the range of 0.02–0.1 µg/L. [ABSTRACT FROM AUTHOR]

A novel plate-like nano-sorbent based on copper/cobalt/chromium layered double hydroxide was synthesized by a simple coprecipitation method. The synthesized nanoparticels were introduced into a stainless steel cartridge using a dry packing method. Then, the packed cartridge was introduced as a novel on-line "packed in-tube" configuration and followed by high performance liquid chromatography for the determination of trace amounts of ∆ 9-tetrahydrocannabinol from biological samples and cannabis leaves. The as-prepared sorbent exhibited long lifetime, good chemical stability, and high anion-exchange capacity. Several important factors affecting the extraction efficiency, such as extraction and desorption times, pH of the sample solution and flow rates of the sample and eluent solutions, were investigated and optimized. Under optimized conditions, this method showed good linearity for ∆ 9-tetrahydrocannabinol in the ranges of 0.09-500, 0.3-500, and 0.4-500 µg/L with coefficients of determination of 0.9999, 0.9991, and 0.9994 in water, serum and plasma samples, respectively. The inter- and intra-assay precisions (n = 3) were respectively in the ranges of 1.8-4.6% and 1.9-4.0% at three concentration levels of 10, 50, and 100 µg/L. The limits of detection were also in the range of 0.02-0.1 µg/L., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)