Optimisation and evaluation of zinc in food samples by cloud point extraction and spectrophotometric detection / Nurul Azwa Mohd Azizi … [et al.]

The cloud point extraction (CPE) method was developed to determine the zinc prior to Ultraviolet-visible (UV-Vis) spectrophotometry detection. Triton X-100 was applied as extractant based on the complexation reaction of Zn(II) ions with ethylenediaminetetraacetic acid (EDTA). Under optimal conditions, the CPE was used to determine the concentration of zinc in canned food samples. The amounts of zinc found in the food samples were in the range of 0.005-0.007 mg/L with relative standard deviation (RSD) of < 8 %. This confirmed that the proposed CPE method is suitable for the determination of zinc in food samples, indicating the concentration of zinc was within the permissible limit

Polyaniline modified magnetic nanoparticles coated with dicationic ionic liquid for effective removal of rhodamine B (RB) from aqueous solution

Polyaniline (PANI) modified magnetic nanoparticle (MNP) nanocomposites coated with newly synthesized dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesized as a potential material for the removal of Rhodamine B (RB) from water samples. The synthesized material was successfully characterized using a few techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and transmission electron microscopy (TEM) analysis. Several parameters have been optimized to enhance the efficiency of the removal process. The adsorption kinetics were investigated and the results showed that MNP-PANI-DICAT was best fitted to a pseudo-second order model for the adsorption of RB. As for the isotherm studies, Temkin's model was found to fit well with the adsorption isotherm of RB on MNP-PANI-DICAT. Other than that, thermodynamics results showed negative values of DG� for the adsorption of RB, which indicated that the process is thermodynamically feasible, spontaneous and chemically controlled at lower temperature. The negative value of enthalpy DH� (40.41) indicated that the adsorption was an exothermic process. The percentage removal of RB was found to be 94.7% by MNP-PANI-DICAT under optimized conditions

Removal of Phosphate by Paper Mill Sludge: Adsorption Isotherm and Kinetic Study

Phosphate ions have been removed from aqueous solution by paper mill sludge. The influences of experimental conditions such as pH, amount of adsorbent, initial concentration of phosphate, adsorption isotherm and adsorption kinetics of paper mill sludge were studied. The adsorption of phosphate was more efficient in the basic pH region (pH 12). Pseudo second-order model fits better than the pseudo first-order model for adsorption kinetic data and indicates the adsorption process is based on chemisorptions. The calculated activation energy (Ea) is 37.01 J/mol which further suggests that the sorption of phosphate by paper mill sludge was based on chemical adsorption. Consequently, the equilibrium isotherm data were fitted well to Langmuir isotherm with maximum adsorption capacity of 12.65 mg/g. From the study, it showed that paper mill sludge has the potential to be utilized as a cost effective and high capability adsorbent for removal of phosphate from aqueous solutions

Determination of phenanthrene and fluoranthene in rice samples by activated carbon-based dispersive solid phase micro-extraction coupled with gas chromatography-flame ionization detector analysis

A simple dispersive solid phase micro-extraction (DSPME) based on activated carbon (AC) was performed for the determination and separation of carcinogenic polycyclic aromatic hydrocarbons (PAHs), namely phenanthrene and fluoranthene, in selected white, brown and parboiled rice samples. The extraction was coupled with gas chromatography-flame ionization detector (GC-FID) for analysis. Under the optimized conditions [amount of adsorbent (5 mg), sample volume (40 mL), type (dichloromethane), and volume of desorption solvent (300 μL)], calibration curves were found to be linear for the concentration between 10 and 1000 μg kg-1 with coefficient of determination (R2) from 0.9938 to 0.9955. The limit of detection (LOD) and limit of quantification (LOQ) were in the range of 0.11 - 0.15 μg kg-1 and 0.33 - 0.46 μg kg-1, respectively. Relative standard deviation (RSD) was less than 8.02% and 5.48% for intra-day (n = 5) and inter-day (n = 5) for the present method, respectively. High pre-concentration factor (2587 - 2866) and satisfactory recoveries (90.23 - 115.63%) were also achieved. The proposed method was found to be simple, rapid and reliable for the monitoring of PAHs in rice samples

Inclusion of curcumin in β-cyclodextrins as potential drug delivery system: preparation, characterization and its preliminary cytotoxicity approaches

The development and application of organic based drug carrier in drug delivery system (DDSs) with greater efficacy and fewer side effects remains a significant challenge in modern scientific and medical research. The aim of current study was to evaluate the ability of β-cyclodextrin (β-CD) as drug delivery carrier to encapsulate Curcumin (CUR), a promising chemotherapeutic that exhibits low aqueous solubility and poor bioavailability forming inclusion complex by kneading method to enhance its delivery to cancer cells. Different methods and analysis such as Fourier Transform Infrared (FTIR) spectrometer, 1H Nuclear Magnetic Resonance (1H NMR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Thermo-gravimetric Analysis (TGA) were employed to approve the successful formation of the inclusion complex where the aromatic ring of CUR has been encapsulated by the hydrophobic cavity of β-CD. UV absorption indicated that β-CD complex with CUR with an apparent formation constant of 1.09 × 10-8mol-1dm-3. Based on the data obtained by methylthiazole tetrazolium (MTT), β-CD showed that not only did it enhanced Curcumin delivery, but it also improved and promoted the anti-proliferative effect of CUR during the complexation rather than CUR alone on the MCF-7 human breast cancer cells at 24 h incubation period with IC50 lower than that of Curcumin alone. The toxicities of the β-CD-CUR towards MCF-7 cells were also compared to the free tamoxifen, Curcumin and β-CD. This study provides a preliminary toxicity evaluation based on β-CD-CUR inclusion complex as potential delivery system towards the selected cancer cells

Application of a new choline-imidazole based deep eutectic solvents in hybrid magnetic molecularly imprinted polymer for efficient and selective removal of naproxen from aqueous samples

A magnetic molecularly imprinted polymer (Fe3O4@MIP) with naproxen (as template) was successfully prepared by adding a co-solvent consisting of a choline-imidazole based deep eutectic solvent (ChCl-BuIM) during polymerisation. The morphological, functional group, and magnetic characteristics of the synthesised materials were characterised by elemental analysis, Fourier transform-infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. This hybrid Fe3O4@MIP-ChCl-BuIM material was used as a magnetic adsorbent for efficient and selective removal of naproxen from wastewater samples. A batch adsorption study showed that adsorption of naproxen onto the multilayer surface of the adsorbent through a chemisorption mechanism. The data showed that the adsorption was feasible, spontaneous, and exothermic. The Fe3O4@MIP-ChCl-BuIM removed more naproxen (93.2–97.1%) than Fe3O4@MIP without ChCl-BuIM (83.2–88.9%). This finding confirms that the use of ChCl-BuIM improved both the selectivity and affinity of the MIP adsorbent towards naproxen. Competitive recognition studies of the Fe3O4@MIP-ChCl-BuIM using naproxen and structurally similar non-steroidal anti-inflammatory drugs revealed that the Fe3O4@MIP-ChCl-BuIM had high selectivity for naproxen. A cytotoxicity test showed that the synthesised ChCl-BuIM was non-toxic, as the human normal cell lines MCF-10A, and BEAS-2B maintained viability above 50%. These results show that Fe3O4@MIP-ChCl-BuIM has potential for use as a functional adsorption material for the removal of naproxen from water samples

Biocompatible nutmeg oil-loaded nanoemulsion as phyto-repellent

Plant essential oils are widely used in perfumes and insect repellent products. However, due to the high volatility of the constituents in essential oils, their efficacy as a repellent product is less effective than that of synthetic compounds. Using a nanoemulsion as a carrier is one way to overcome this disadvantage of essential oils. Nutmeg oil-loaded nanoemulsion (NT) was prepared using a high speed homogenizer and sonicator with varying amounts of surfactant, glycerol, and distilled water. Using a phase diagram, different formulations were tested for their droplet size and insect repellent activity. The nanoemulsion containing 6.25% surfactant and 91.25% glycerol (NT 6) had the highest percentage of protection (87.81%) in terms of repellent activity among the formulations tested for the 8 h duration of the experiment. The droplet size of NT 6 was 217.4 nm, and its polydispersity index (PDI) was 0.248. The zeta potential value was -44.2 mV, and the viscosity was 2.49 Pa.s at pH 5.6. The in vitro release profile was 71.5%. When the cytotoxicity of NT 6 at 400 μg/mL was tested using the MTS assay, cell viability was 97.38%. Physical appearance and stability of the nanoemulsion improved with the addition of glycerol as a co-solvent. In summary, a nutmeg oil-loaded nanoemulsion was successfully formulated and its controlled release of the essential oil showed mosquito repellent activity, thus eliminating the disadvantages of essential oils

Conventional Study on Novel Dicationic Ionic Liquid Inclusion with β-Cyclodextrin

This study focuses on the synthesis and characterization of the inclusion complex of β-Cyclodextrin (β-CD) with dicationic ionic liquid, 3,3′-(1,4-Phenylenebis [methylene]) bis(1-methyl-1H-imidazol-3-ium) di(bromide) (PhenmimBr). The inclusion complex was prepared at room temperature utilizing conventional kneading technique. Proton (1H) NMR and 2D (1H–1H) COSY NMR were the primary characterization tools employed to verify the formation of the inclusion complex. COSY spectra showed strong correlations between protons of imidazolium and protons of β-CD which indicates that the imidazolium ring of PhenmimBr has entered the cavity of β-CD. UV absorption indicated that β-CD reacts with PhenmimBr to form a 2:1 β-CD-PhenmimBr complex with an apparent formation constant of 2.61 × 105 mol&−2 L2. Other characterization studies such as UV, FT-IR, XRD, TGA, DSC and SEM studies were also used to further support the formation of the β-CD-PhenmimBr inclusion complex

Preparation and use of maize tassels’ activated carbon for the adsorption of phenolic compounds in environmental waste water samples

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84–98.49 %, 80.75–97.11 %, and 78.27–97.08 % for BPA, o-NTP, and PCP, respectively) . The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes