Optimization and determination of Tartrazine by Green Tween-20 cloud point extraction for food samples / Nurulhazirah Mohd Nasir... [et al.]

A simple and low-cost cloud point extraction (CPE) method was developed for the determination of tartrazine in food samples by spectrophotometry detection at a wavelength 427.5 nm. The CPE was performed by utilizing Tween-20 and sodium carbonate (Na 2 CO 3 ) as extractant and separation accelerator, respectively. Factors that influenced CPE such as surfactant and salt concentrations, pH and temperature were optimized in the context of extracting tartrazine from aqueous media. Under an optimal condition, the proposed CPE was applied for the determination of tartrazine in sweets and concentrated syrup juice, which represented food samples. A CPE-UV-Vis method showed linear calibration within the range of 1-12 mg L -1 of tartrazine with a regression coefficient was 0.9957. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.88 mg L -1 and 2.96 mg L -1 , respectively. The relative standard deviation (RSD) was found to be < 3.00 %. The amount of tartrazine found in food samples was 1.22-6.12 mg L -1 . The results showed that the proposed CPE method was applicable for the determination of tartrazine in food samples and the tartrazine content in the food samples was permitted according to the guidelines from the European Food Safety Authority (EFSA)

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

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

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

Ultrasound-assisted surfactant enhanced emulsification microextraction method coupled with gas chromatography-mass spectrometry for the determination of selected polycyclic aromatic hydrocarbons in aqueous samples

A simple and rapid microextraction method termed as ultrasound-assisted surfactant enhanced emulsification microextraction (UASEME) was developed for the determination of fluoranthene (FLU) and phenanthrene (PHE) in aqueous samples followed by gas chromatography-mass spectrometry (GC-MS). Six important parameters, that affect the extraction efficiency of polycyclic aromatic hydrocarbons (PAHs) were evaluated and the results were as follows; extraction solvent (toluene), volume of extraction solvent (30 μL), surfactant (Tween 20), volume of surfactant (15 μL), extraction time (2 minutes) and with no salt addition. Under the optimum conditions, the method showed good linearity over the concentration range from 1 – 1000 μg L- 1 with correlation coefficients (R² ≥ 0.9932), acceptable limits of detection (0.3 μg L- 1) and limits of quantification (1.0 μg L- 1) for both analytes. Good relative recovery values, in the range of 91.75 – 104.1%, were obtained for tap water samples. The relative standard deviations (RSDs) were 1.62 – 10.32% (n = 3). The proposed method was applied for the determination of FLU and PHE in tap water and sugarcane juices

The impacts of traditional eastern diet on the community health and environment sustainability

Traditional Eastern diets are often based on grains, beans, and other healthful foods. It is usually low in red meat and rich in whole grains, vegetables, fruits, and seafood [1]. According to the World Health Organization, a healthy diet includes fruits, vegetables, legumes, nuts, whole grains, meat, fish, eggs, and milk. Each intake varies depending on individual characteristics such as age, gender, lifestyle, and level of physical activity. A healthy diet is essential because it provides a balanced diet to protect against many chronic non-communicable diseases, such as heart disease, diabetes, and cancer [2]. Healthy and sustainable food choices contribute to a series of Sustainable Development Goals, including SDG 2, SDG 3, SDG 11, and SDG 12. These goals are to ensure food security, an improvement in health and well-being, sustainable cities, and communities, and lastly, responsible consumption and production

A study on biological sample preparation for high resolution imaging of scanning electron microscope

Green chemistry has drawn attention for synthesizing nanoparticles as it utilizes an eco-friendly nontoxic chemical in the synthesis protocol. In addition, researchers start looking into the potential of organism such as bacteria, fungi and plants for synthesizing nanoparticles. Synthesis of nanoparticles requires details on structural analysis before/after synthesis in order to evaluate and control the quality of nanoparticles. Scanning electron microscope (SEM) has been widely used as an imaging instrument to structurally characterize nanoparticles before/after synthesis process. Maintaining the vacuum level in SEM system and controlling contamination originated from the sample are crucially important to enable high resolution imaging. In addition, sample surface need to be conductive to prevent image distortion due to the electron charging effect. Hence, raise the importance to study the method in preparing biological sample for SEM imaging. This work focuses on the three approaches of drying process for plant, bacteria and algae samples. Proper selection of preparation method on each samples involving air-drying using HMDS, CPD and FD methods have been done in order to prevent surface tension effect during drying process, which will result in the modification of the original structure. Comparison was made to get insight on the suitable sample preparation method for the specific biological sample. It is found that air-drying or CPD methods are suitable for the liquid-rich biological sample, while FD method can be a preference for biological sample that contains less liquid

Polyaniline-dicationic ionic liquid coated with magnetic nanoparticles composite for magnetic solid phase extraction of polycyclic aromatic hydrocarbons in environmental samples

In this present study, magnetic nanoparticles (MNPs) nanocomposites modified with polyaniline (PANI) coated newly synthesised dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesised as new generation material for magnetic solid phase extraction (MSPE). MNP-PANI-DICAT was characterised by FT-IR NMR, CHN, BET, SEM, TEM, and VSM techniques and the results were compared with MNP-PANI and native MNP. This new material was applied as a magnetic adsorbent for the pre-concentration and separation of polycyclic aromatic hydrocarbons (PAHs) due to the π–π interaction between polyaniline shell and dicationic ionic liquid (DICAT) with PAHs compounds. Under the optimal conditions, the proposed method was evaluated and applied for the analysis of PAHs in environmental samples using gas chromatography-mass spectrometry (GC-MS). The validation method showed good linearity (0.005–500 µg L−1) with the coefficient of determination (R2) > 0.999. The limits of detection (LOD) and quantification (LOQ) of the developed method (MNP-PANI-DICAT-MSPE) were in the range of 0.0008–0.2086 µg L−1 and 0.0024–0.6320 µg L−1, respectively. The enrichment factor (EF) of PAHs on MNP-PANI-DICAT-MSPE were in the range of 7.546–29.632. The extraction recoveries of natural water, sludge, and soil samples were ranged from 80.2% to 111.9% with relative standard deviation (RSD) less than 5.6%. The newly synthesised MNP-PANI-DICAT possess good sensitivity, reusability, and fast extraction of PAHs under the MSPE procedure in various environmental samples

Enantiomeric separation of azole antifungal compounds using chromatographic and electrophoretic techniques: a mini review

The separation of azole antifungal chiral compounds has gaining much interests since 1980’s as they possess different biological, pharmaceutical, and pharmacokinetic behaviors at various toxicity levels. Numerous studies have looked into this subject matter, and therefore, this review presents an overview on different chiral separation techniques that have been developed such as liquid chromatography (LC), gas chromatography (GC), supercritical fluid chromatography (SFC), and capillary electrophoresis (CE). This comprehensive review also discusses the mechanisms of the developed analytical methods such as preparation techniques and optimization parameters towards the enantioseparation performances as well as their advantages and drawbacks. Lastly, the conclusion and future directions of the chiral separation, particularly for azole compounds are provided accordingly

Performance analysis and green profile assessment of synthesised amino-functionalised magnetic silica nanocomposite for magnetic micro-solid phase extraction of penicillin antibiotics from milk samples

This study explored the synthesis and application of amino-functionalised magnetic silica (Fe3O4 @mSiO2-NH2) nanocomposite as a selective sorbent for the extraction of penicillin antibiotics (PENs) from milk samples via magnetic micro-solid phase extraction (M-µ-SPE). The physicochemical characteristics of the synthesised sorbent were evaluated through important spectroscopy analyses. The adopted M-µ-SPE conditions were: 25 mg of Fe3O4 @mSiO2-NH2; pH 4; 3 min of extraction time; 1 min of desorption time; acetonitrile as the desorption solvent; 10 of salt addition; and 30 mL sample. Under the optimum conditions, the developed method demonstrated satisfactory from 10 to 500 µg/L (r2≥0.9986), low limits of detection (2.5–3.1 µg/L), high analytes recovery (85.2–106.7), and good precision (RSDs≤8,n = 5). The proposed method is rapid, simple, inexpensive, and shows good sensitivity when compared to previously developed methods. This study provides new insight into the development of a new sorbent for PENs and new microscale sample preparation for monitoring PENs in complex milk matrices