Silica Gel Chemically Modified with Ionic Liquid as Novel Sorbent for Solid-Phase Extraction and Preconcentration of Lead from Beer and Tea Drink Samples Followed by Flame Atomic Absorption Spectrometric Determination

An automatic on-line sol-gel pyridylethylthiopropyl functionalized silica-based sorbent extraction system coupled to flame atomic absorption spectrometry for lead and copper determination in beer samples

A novel sol-gel pyridylethylthiopropyl functionalized silica-based sorbent was synthesized and utilized in an on-line column preconcentration system coupled with flame atomic absorption spectrometry for metal determination. The developed platform was used for the determination of Pb(II) and Cu(II) in beer samples, since there are limited automatic methods for routine analysis of alcoholic beverage. For a preconcentration time of 60 s, the calculated enhancement factors were 96 for Cu(II) and 130 for Pb(II). The limits of detection were 0.33 μg L^-1 and 1.98 μg L^-1 for Cu(II) and Pb(II), respectively. Moreover, the RSDs were less than 2.9% indicating good method precision. The method was successfully employed for the analysis of commercially available beers. The Cu(II) content of the samples was 1.6-21.8 μg L^-1 and the Pb(II) content was 7.3-17.6 μg L^-1. The developed manifold exhibited operational simplicity and good performance characteristics, indicating its potential utilization for routine analysis in beer industry.

Enhanced removal of As(Ⅲ) and As(Ⅴ) from aqueous solution using ionic liquid-modified magnetic graphene oxide

In this study, ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆])-modified magnetic graphene oxide (MGO-IL) was prepared for the first time, and was used to adsorb and remove arsenic (As(Ⅲ) and As(V)) ions from aqueous solution. MGO-IL was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and magnetization curves. Effects of ionic liquid type, solution pH, initial arsenic concentration and contact time on the adsorption performance of MGO-IL for As(Ⅲ) and As(V) were studied. The experimental results showed that the adsorption equilibrium was achieved within 30 min, with maximum adsorption capacities of 160.65 mg g^-1 for As(Ⅲ) and 104.13 mg g^-1 for As(V), respectively, and MGO-IL could be rapidly isolated from solution by applying a magnetic field. MGO-IL was reused for 5 times, without marked decrease in its adsorption capacities. Moreover, common coexisting anions did not interfere with the absorption of As(Ⅲ) and As(V). Compared with MGO, the sorption quantities of MGO-IL for As(Ⅲ) and As(V) were greatly enhanced, and the equilibrium time was significantly reduced. Therefore, MGO-IL can potentially serve as an excellent adsorbent for the simultaneous separation and removal of As(Ⅲ) and As(V) from water.

Silica-coated magnetic iron oxide functionalized with hydrophobic polymeric ionic liquid: a promising nanoscale sorbent for simultaneous extraction of antidiabetic drugs from human plasma prior to their quantitation by HPLC

Herein, silica-coated iron oxide nanoparticles modified with imidazolium-based polymeric ionic liquid (Fe₃O₄@SiO₂@PIL) were fabricated as a sustainable sorbent for magnetic solid-phase extraction (MSPE) and simultaneous determination of trace antidiabetic drugs in human plasma by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The Fe₃O₄ core was functionalized by silica (SiO₂) and vinyl layers where the ionic liquid 1-vinyl-3-octylimidazolium bromide (VOIM-Br) was attached through a free radical copolymerization process. In order to achieve hydrophobic magnetic nanoparticles and increase the merits of the sorbent, Br⁻ anions were synthetically replaced with PF₆⁻. The properties and morphology of the sorbent were characterized by various techniques and all the results illustrated the prosperous synthesis of Fe₃O₄@SiO₂@PIL. A comprehensive study was carried out to investigate and optimize various parameters affecting the extraction efficiency. The limit of detection (LOD, S/N = 3) for empagliflozin, metformin and canagliflozin was 1.3, 6.0 and 0.8 ng mL⁻¹, respectively. Linearity (0.997 ≥ r² ≥ 0.993) and linear concentration ranges of 5.0–1200.0, 20.0–1800.0 and 5.0–1000.0 ng mL⁻¹ were obtained for empagliflozin, metformin and canagliflozin, respectively. Intra-assay (3.8–7.5%, n = 9) and inter-assay (3.2–8.5%, n = 12) precisions as well as accuracies (≤9.1%) displayed good efficiency of the method. Finally, the method was applied for the quantitation of antidiabetic drugs in human plasma after oral administration and main pharmacokinetic data including T_max (h), C_max (ng mL⁻¹), AUC_0–24 (ng h mL⁻¹), AUC_0–∞ (ng h mL⁻¹), and T_1/2 (h) were evaluated.

A sustainable nanoscale core–shell modified with hydrophobic polymeric ionic liquid was fabricated for simultaneous extraction and determination of antidiabetic drugs.

Synthesis and characterization of a novel chloromethylated polystyrene-g-2-adenine chelating resin and its application to preconcentrate and detect the concentration of mercury ions in edible mushroom samples

Edible mushrooms are widely usedtoday but the heavy metal pollution of edible mushrooms is not conducive to its industrialization. A novel chloromethylated polystyrene-g-2-adenine chelating resin (AR resin) with simple technology, high adsorption capacity, significant selectivity, and good regenerability was synthesized. Combined with the UV-Vis method, it was applied to mercury preconcentration and determination. The results indicated that the AR resin is essentially free from interferences, which can contribute to accurate determination in waters and foods. Optimization of the resin synthesis was carried out by using response surface methodology. The adsorption properties of the resin for Hg(II) were investigated by batch and column experiments. The statically and dynamic saturated adsorption capacities were 383.4 and 417.0 mg/g. The adsorption kinetic and equilibrium data were well fitted to the second-order model and the Langmuir isotherm model, respectively. Furthermore, the resin and its metal complexes were studied by Fourier transform infrared spectroscopy and thermogravimetric analysis.