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

Evaluation of Extra Virgin Olive Oil Adulteration with Edible Oils using ATR-FTIR Spectroscopy

Extra virgin olive oil (EVOO) is categorized as expensive oil due to high-quality nutritional value. Unfortunately, EVOO is easily adulterated with other low-quality edible oils. Therefore, this study was done to differentiate and analyze the adulteration of EVOO with other edible oils using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The study was used several edible oils included canola oil, corn oil, sunflower oil, and soybean oil as an adulterant for EVOO. The adulterant EVOO samples were prepared by mixing with dissimilar concentrations of the solely edible oils (20 %, 40 %, 60 % and 80 % (v/v)). The main functional groups of EVOO and other edible oils are O-H, C-H, C=C and C=O groups were assigned around 3500 cm-1, 2925 cm-1, 3006 cm-1 and 1745 cm-1 wavenumbers, respectively. From the comparison of EVOO and other adulterant edibles oil spectra, it showed that the EVOO has the lowest absorbance intensity at around 3006 cm-1 represented double bond which is closely related to the composition of oil sample. The adulteration of EVOO was evaluated by analysing the changes in the absorbance based on the linear regression analysis graph of the bands at 3006 and 2925 cm-1 and the limit of detection (LOD) was measured. The graph of A3008/A2925 with good relative coefficients (R2) and lower LOD is more favourable than the linear regression graph of A3006 versus percentage of edible oils added in EVOO. This study showed that ATR-FTIR spectroscopy is a convenient tool for analysing the adulteration of EVOO

β-Cyclodextrin functionalized ionic liquid as high performance liquid chromatography chiral stationary phase for the enantioseparation of natural products and pharmaceuticals / Nurul Yani Rahim

The demanding for enantiomerically pure (enantiopure) compounds, especially for pharmaceutical field has been attracting great attention during last decades. Direct enantioseparation by chiral stationary phases (CSPs) using high performance liquid chromatography (HPLC) remains as the most important technique for enantioseparation. The development of novel stable and powerful CSPs is therefore important. The first part of this study involved a facile and reliable preparation of CSPs. Thus, β- cyclodextrin was functionalized with ionic liquids (ILs) namely 1-benzylimidazole (1- BzlIm) and 1-decyl-2-methylimidazole (C10MIm) with tosylate as anion produced β- CD-BIMOTs and β-CD-DIMOTs respectively. β-CD-BIMOTs and β-CD-DIMOTs were attached to the modified silica to obtain the CSPs. The performances of the synthesized CSPs were determined by examining the capability of enantioseparation of selected analytes: flavonoids (flavanone, hesperetin, naringenin and eriodictyol), β- blockers (atenolol, metoprolol, pindolol and propranolol) and Non-steroidal antiinflammatory drug (NSAIDs) (ibuprofen, fenoprofen, ketoprofen and indoprofen). The performance of β-CD-BIMOTs and β-CD-DIMOTs stationary phases was also compared with native β-CD stationary phase. The results indicated that β-CD-BIMOTs stationary phase afforded more favorable enantioseparations than β-CD-DIMOTs and native β-CD based stationary phases. Therefore, the optimization for enantioseparation of selected analytes (flavonoids, β-blockers and NSAIDs) and evaluation of interactions was further investigated on β-CD-BIMOTs stationary phase. The selected flavonoids, flavanone and hesperetin obtained high resolution factor in reverse phase mode. Meanwhile naringenin and eriodictyol attained partial enantioseparation in polar organic mode. In order to understand the mechanism of separation, the interaction of selected flavonoids and β-CD-BIMOTs was studied using spectroscopic methods which are 1H NMR, NOESY and UV/Vis spectrophotometry. The result for enantioseparation of selected β-blockers, propranolol and metoprolol showed good enantioresolution compared to atenolol and pindolol. The results suggested that the lipophilic property and the structure of propranolol and metoprolol that enable the formation of inclusion complex contribute to better enantioseparation. This observation was proven by 1H NMR and NOESY of β-CD-BIMOTs/β-blockers. The effect of the types and variation of mobile phase composition on enantioseparation of NSAIDs was also studied on β- CD-BIMOTs CSP. From the result of enantioseparation, ibuprofen and indoprofen achieved the better resolution than ketoprofen and fenoprofen due to their favorable orientation to fit into the β-CD-BIMOTs cavity. This orientation was depending on the structure of NSAIDs

Extraction behaviour of Cu(II) and Fe(III) from chloride medium to the hydrophobic ionic liquids using 1,10-phenanthroline / Nurul Yani Rahim

The study of liquid-liquid extraction of Cu(II) and Fe(III) ion was carried out using a series of hydrophobic ionic liquid; 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mimPF6]), 1-hexyl-3-methylimidazolium hexafluorophospahate ([C6mimPF6]), 1-butyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C4mimNTf2]) and 1-hexyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C6mimNTf2]) as the extraction phase. Cu(II) showed a preferential extraction into less hydrophobic ionic liquid, [C4mimPF6]. The extraction behavior of Cu(II) ions depend on the type of counter ion present. The extraction process of Cu(II) ion in ionic liquid proceeded via similar mechanism to that of a molecular organic solvent. From the results obtained, an ion pair mechanism is proposed for the extraction of Cu complexes from chloride medium. Fe(III) favors extraction into [C6mimNTf2], the most hydrophobic ionic liquid. Anion exchange is the mode of extraction of Fe complexes from chloride medium

Influence of degree of substitution on the host-guest inclusion complex between ionic liquid substituted β-cyclodextrins with 2,4-dichlorophenol: An electrochemical, NMR and molecular docking studies

A mono- and di-substituted ionic liquid-β-cyclodextrin (β-CD-ILs) were synthesized and their host-guest inclusion complex with 2, 4-dichlorophenol (2,4-DCP) were evaluated by electrochemical study. First, both β-CD-ILs which is β-CD-1-BIMOTs and β-CD-2-BIMOTs were fabricated on carbon paste electrode (CPE) for determination of 2,4-DCP. The cyclic voltammetry results indicate that both β-CD-IL/CPEs exhibit higher oxidation peak current compared to native β-CD/CPE. Both complexes possess high sensitivity, stability and reproducibility. However, as the degree of substitution of ionic liquid (IL) increases, the selectivity of β-CD-IL towards 2,4-DCP decreases. Thus, it can be deduced that the degree of substitution of IL is influencing the host-guest inclusion complex of β-CD-ILs with 2,4-DCP. © 2019 Elsevier B.V

Surface Functionalization of Magnetite Nanoparticles for Remediation Enhancement of Phenol from Aqueous Solutions

Phenol is a toxic pollutant generated by industries. It can diminish the supply of clean water and is hazardous to human health. Hence, an effective abatement method is important to remove phenol from water sources. The following amine-functionalized magnetite nanoparticles, ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and polyethylenehexamine (PEHA), were used to study the adsorption performances of phenol from the prepared samples. The morphological study revealed long rod shapes with rough and sharp edges, while the elemental analysis presented the addition of two elements, C and N atoms. In addition, the TETA@MNP possessed weaker magnetism compared to MNPs, showing that the surface functionalization of MNPs was successful. TETA@MNP showed the highest percentage for phenol removal compared to others. The TETA@MNP achieved a removal efficiency of 99.2% at optimum conditions of 60 mg dosage, contact time of 25 min, and pH of 7. TETA@MNP obeyed the pseudo-second-order kinetic model and the Freundlich isotherm model, with coefficients of determination (R2) of 0.9765 and 0.9682, respectively. The reusability study has demonstrated that TETA@MNP can be reused approximately 6 times with extremely minor loss. Therefore, TETA@MNP is a good adsorbent for the adsorption of phenol from prepared sample solutions