Analytical and Bioanalytical Chemistry Research
Volume:11 Issue: 1, Winter 2024

Traditional techniques for adding chelating agents to solids take time, energy, and materials. This study focuses on the preparation of a quick and easy solid-phase extraction approach using microwave-enforced green synthesis. CuFe2O4 magnetic nanoparticles (CFO-NPs) were modified chemically by bis(salicylaldehyde) phenylenediamine (BSAPhD) investigated for Cu(II) removal from aqueous solutions. The modification conditions (power and time) of the process are optimized. The performance of the resulting magnetic composite nanoparticles (BSAPhD@CFO-NPs) was compared with that of those prepared using a conventional reflux method (BSAPhD/reflux@CFO). BSAPhD@CFO-NPs was characterized using Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). All the data confirmed the success of the preparation of BSAPhD and modification for CFO with BSAPhD via microwave synthesis. The experimental adsorption conditions: pH, contact time, adsorbent mass, and Cu(II) concentration were also optimized. BSAPhD@CFO-NPs has an adsorption capacity of 429.8 mg-Cu(II) g–1, which is more than that of BSAPhD/reflux@CFO (287 mg g-1) at pH = 8 with 15 min contact time. The Freundlich, Langmuir, and Temkin isotherms are used to describe adsorption equilibrium. It was found that the Langmuir model (R2 = 0.9988) best fits Cu(II) adsorption on the BSAPhD@CFO-NPs adsorbent surface. The application of the BSAPhD@CFO-NPs adsorbent for the removal of Cu(II) from various water samples was performed. The results showed good recovery with high sensitivity.

For the first time, air-assisted cloud point extraction (AA-CPE) procedure was applied to determine selenium in black tea samples at room temperature. The Air agitation is powered by a small fish tank generator to improve the dispersion phase and reduce the critical temperature for surfactants. The ligand and surfactant were 1-(2-hydroxy-5-ptolylazo-phenyl)-ethan-one (HPAPEO) and TritonX-100, respectively. Afterwards, the extracted selenium complexes were injected into a hydride generation atomic absorption spectrometer (HG-AAS). At the optimal conditions of experimentation, a linearity from 0.3 to 1000 µg L-1 was constructed with an enhancement factor, preconcentration factor, detection limit, and extraction recovery of 150, 100, 0.02 µg L-1, and 99.1–102%, respectively. The AA-CPE technique's accuracy has been proven using certified reference materials. Ultimately, the Red-Green-Blue (RGB12), Analytical Greenness Metric Approach (AGREE), and Complementary Green Analytical Procedure Index (ComplexGAPI) scales have been applied to assess the whiteness and greenness of this method. An accurate evaluation of the criteria has been performed to ensure this procedure is eco-friendly for the environment.

The study describes the adsorption of Lead ion from aqueous solution using Sugarcane bagasse. Bagasse is a fibrous residue from Sugar mills, is not easily biodegradable posing disposal challenges. Given its abundance in the sugar producing regions of Nigeria, there is continued need to find other alternative uses. The objective of this study was to investigate the potential use of sugarcane bagasse-based adsorbents for removing Pb, from contaminant water. Sugarcane bagasse was used for removal of Pb ion from aqueous solutions as an efficient adsorbent. The response surface methodology (RSM) was applied for experimental design of adsorption from aqueous solutions. The effect of three independent variables including contact time, Adsorbent dosage and Pb ion concentration on the percentage removal (R (%) was studied. For this purpose, 13 runs of experiments that was designed by the Design–Expert software were performed. The optimum conditions for contact time, Adsorbent dosage and Pb ion concentration were found as 4.5hrs, 8g and 100ppm, respectively. At these conditions, percentage removal was to be 99.2%. It is evident that bagasse-based adsorbents can effectively remove Pb, from contaminated water. It is therefore recommended that the bagasse-based adsorbents can be utilized to remove Pb from contaminated water but more studies need to be conducted with actual contaminated water from various sources to determine their efficacy as adsorbents.

The combination of aptamer is performed with molecularly imprinted (MIP) using their unique features. In this sense, first the screen-printed carbon electrode (SPCE) was modified with nano size iridium cupper on nitrogen-doped carbon nanocapsoul (CN@IrCu) and, then, the Aptamer -MIP hybrid was used to detect Helicobacter pylori. This design leads to the use of dual properties of Aptamer and MIP. Moreover, CN@IrCu has been used as a substrate to increase aptamer loading and the conductivity. The sensing surface fabrication steps was measured by several different electrochemical techniques such as cyclic voltammetric (CV), differential pulse voltammetric (DPV), electrochemical impedance spectroscopy (EIS). The sensor shows a linear range from 102 CFU.ml-1 to 107 CFU.ml-1 with a detection limit of 33 CFU.ml-1. This Aptamer-MIP/CN@IrCu/SPCE was successfully evaluated in determining the concentration of Helicobacter pylori in blood serum samples with high reproducibility and selectivity. This MIP-aptasensor is low cost, low response time, high stability and good sensitivity.

In this work, walnut green husk has been used as a simple, cheap, biodegradable, and efficient adsorbent in dispersive solid phase extraction of Cd (II) and Pb (II) ions from some oil samples including edible, fish oil, and butter. In the next step, a dispersive liquid-liquid microextraction method was used to enrich the extracted analytes before their analysis with flame atomic absorption spectrometry. For this purpose, the adsorbent was obtained from agricultural wastes, dried in an isolated environment at ambient temperature, and mechanically ground to obtain a homogeneous powder. The parameters affecting the efficiency of the method were optimized. Low detection limits (0.12 and 0.32 µg L-1 for Cd (II) and Pb (II), respectively), low relative standard deviations (3.8% and 4.2% for Cd (II) and Pb (II), respectively) and determination coefficients close to 1 (0.991 and 0.995 for Cd (II) and Pb (II), respectively) were achieved. Also, the extraction recoveries for the target analytes were 89 and 96% for Cd (II) and Pb (II), respectively.

The commonly used polymeric disinfectants, didecyldimethylammonium chloride (DDAC) and polyethylene glycolmonoalkyl ether (GEN) can drift with water vapor and aerosols, although they are not volatile. When being in aerosols, the amines of them have justified to irritate respiratory organs of humans. But, when not being in breading air they stay on surfaces due to absorption and accumulation when temperature and moisture of the environment are low.The paper presents a new approach to determine disinfectants in alkaline tetraborate solution using capillary electrophoresis with direct UV detection. DDAC and GEN were investigated to move from surfaces to aerosol. The studied compounds were quantitatively analyzed at low concentrations (1-10 ng mL-1 with RSD 2%) to prevent micelle formation and to guarantee the method specificity. The limits of detection and quantification were 0.006 and 0.018 ng mL-1, and 1.0 and 3.84 ng mL-1 for DDAC and GEN, respectively. They both were studied from 46 samples collected from two school environments which were daily washed with the commercial chemicals. The results showed that concentrations of these biocide-type disinfectants were between 2.5 - 1029 ng mL-1.

In this study, a new sorbent was synthesized based on the in-situ growth of the combined ZIF-67 and ZIF-8 on the surface of MIL101. Finally, the adsorbent was made into a thin film with the help of polyvinylidene difluoride polymer and was used in the TFME technique for the simultaneous measurement of cadmium and lead metals in aqueous and cosmetic samples by means of flame atomic absorption spectroscopy. In order to achieve maximum efficiency and sensitivity, parameters affecting the extraction and desorption processes were optimized. Under the optimized condition, the linearity of the method, the limit of detections (LODs), the limit of quantifications (LOQs), the relative standard deviations (RSDs%), and enrichment factors (EFs) were equal with 0.2–150.0 µg L-1, 0.05968-0.15968 µg L-1, 0.19800-0.47903 µg L-1, 1.2 to 2.5% and 73 - 75, in water matrix, respectively. Then the optimal conditions for Pb and Cd were used in water and cosmetics samples by flame atomic absorption spectroscopy and acceptable results were obtained.

In the present study, HKUST-1 (Hong Kong University of Science and Technology), HKUST-1@PVA, and Fe3O4@HKUST-1, metal-organic framework, were synthesized by hydrothermal, post-synthetic modification and pre-synthetic modification methods, respectively. These sorbents were applied to remove the meloxicam drug as the model drug from aqueous solutions. The adsorption isotherm, kinetic, and thermodynamic experiments were done and confirmed that the adsorption behaviors of HKUST-1, Fe3O4@HKUST-1, and HKUST-1@PVA are based on Langmuir isotherm (the values of qmax were obtained as 883.33, 2.50E+03 mg/g for HKUST-1@PVA and Fe3O4@HKUST-1, respectively) and Freundlich isotherm (the values of KF were obtained as 3.02E+03 (n=0.74), 7.24E+03 (n=0.99) and 7.99E+04 (n=1.49) for HKUST-1, Fe3O4@HKUST-1 and HKUST-1@PVA, respectively), with an endothermic mechanism and enthalpy-driven process. The kinetic results showed well-fitting with the pseudo-second-order kinetic model for all of them. The speed of the adsorption process, low cost, high efficiency, and high surface area are the main advantages of the proposed compounds as sorbents. The functionalization of HKUST-1 with magnetic nanoparticles decreased the adsorption time, and with PVA provides more functional group on the surface of HKUST-1 and increases its adsorption efficiency. Further, an easy separation with an external magnet in 30 seconds is another advantage of magnetic functionalization. The aforementioned features make these adsorbents appropriate candidates for cost-effective water treatment.

Environmental components, especially water, are important for human life and other organism and the sustainability of the earth. Recently, environmental pollution has been one of the most crucial problems globally. Therefore, analytical methods are needed to monitor the water environment pollutant. Electrochemical techniques have been developed for pollutant determination in water environments due to low cost, simplified operations, shorter time for analysis, increased sensitivity, and capabilities for simultaneous detection of multiple substances. One of the most common electrochemical sensors is based on carbon electrodes. Carbon electrodes have many advantages, such as low background current, mechanical strength, inhibition of water electrolysis, and ease to modification. In this review, we described the development of carbon electrodes in electrochemical sensors to determine water pollutants including 4-nitrophenol, tetracycline, diazinon, and heavy metal. This review mentioned the various modified sensors that increase the performance of the sensor including sensitivity, selectivity, and reproducibility. We expect that this review can be used as the basis for developing further modified sensors with excellent performance.

The purpose of this study was to use a hydro-ethanolic solvent to extract natural color extract as effectively as possible from Calendula arvensis flower petals. The effects of ethanol volume, extraction time, and solvent/material ratio on the efficacy of Calendula arvensis flower petal extractives by ultrasonic extraction at 50 kHz and room temperature were investigated. Total phenol content (TPC) and color power were used to quantitatively describe each extract. Using Response Surface Methodology (RSM), the extraction procedure was optimized, and extraction effectiveness was increased (TPC, color power). Different ethanol-to-water ratios were employed in the experiments. Through a variance analysis, the effectiveness of the extraction procedure was established (ANOVA). The maximum extraction efficiency of the hydro-ethanolic extraction (28.21%), the polyphenol content (779.11 mg GAE/g extract), and the color power (42) were quantified using a 30 min treatment time, a 60:40 ethanol:water ratio, and a 15 mL/g solvent/material ratio. The results obtained show that ultrasonic-assisted extraction is a successful technique for extracting natural color from Calendula arvensis.