Speciation of inorganic arsenic by µ-thin-layer chromatography coupled with laser ablation inductively coupled plasma mass spectrometry based on an ion imprinted polymer.

An efficient strategy utilizing µ-thin layer chromatography coupled with laser ablation inductively coupled plasma mass spectrometry (µ-TLC-LA-ICP-MS) based on an IIP (ion imprinted polymer) was developed for the speciation of inorganic arsenic [As(III) and As(V)]. The characterization of the fabricated IIP was performed applying Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). To prepare the thin layer chromatography plate, CaSO4 (as a binder) was incorporated with the IIP. Then, the surface of the TLC plate was swept by LA, which volatilized the species of arsenic from the thin layer chromatography plate which thereafter were introduced into the ICP-MS system. Various effective parameters on isolation efficiency, such as the IIP/CaSO4 mass ratio, mobile phase composition, and pH, were examined. Under optimized conditions, the developed method demonstrated a detection limit of 0.3 µg L-1 with a wide linear dynamic range of 0.2-100 µg L-1, and a relative standard deviation of 3.8. The performance of the developed method was investigated for the isolation of As(III) and As(V) in wastewater (Mouteh, Aghdareh, and Zarmehr mines) and human blood plasma real samples.

Characterization of a traditional ripened cheese, Kurdish Kope: Lipolysis, lactate metabolism, the release profile of volatile compounds, and correlations with sensory characteristics.

Kope cheese has been characterized based on gross chemical composition, free fatty acids (FFAs), organic acids (OAs), volatile compounds (VCs), and sensory attributes (SAs) during 187 days of the ripening period. C16:0, C18:1cisΔ9, and C14:0 were the most abundant FFAs. Lactic and acetic acids were the most prevalent OAs affecting sensory properties. principal component analysis (PCA) indicated that butanoic acid, butyl hexanoate, and 2,3-butanediol were as key VCs. Protein contents, pH (based on FFA and OA), salt in the moisture (S/M), and water activity (aw ) (based on VC and SA) were highly correlated with PC2, resulted in two distinct groups. Based on lipolysis and glycolysis studies, early-ripened cheese samples showed lipolysis and lactate metabolism more intensely compared to medium and old-ripened ones. Based on the data of VC and SA, the samples may be classified into three groups: (1) early-ripened cheeses with a salty taste, waxy to cheesy odor, and rubbery texture, (2) medium-ripened cheese with a sweet taste and cheesy odor, and (3) old-ripened cheese with a bitter taste, cheesy to pungent odor, a firm and fragile texture. Textural attributes were highly correlated with proteolysis indices and pH. The results of sensory desirability indicated a significant correlation with pungency, bitterness, and OAs. The cheese samples ripened on the day 127 were selected as the most desirable product. Ripening time had a significant effect on the chemical composition, especially on S/M, pH, and aw  parameters, which determine the pattern as well as the intensity of biochemical pathways and the final sensory attributes. PRACTICAL APPLICATION: The current study intends to characterize and develop a standardized procedure for producing a traditional cheese called "Kope cheese" by determining the appropriate duration time for the ripening process, determining the main chemical/biochemical compounds that are highly correlated with its unique flavor and texture and distinguishing the key processing factors (such as curd salting, pH values during brining) that have to be altered or controlled carefully during the manufacturing process. The data would help cheese manufacturers determine the optimum time of ripening in order to achieve the best flavor and texture attributes in the final product.

Photodegradation of organic water pollutants under visible light using anatase F, N co-doped TiO2/SiO2 nanocomposite: Semi-pilot plant experiment and density functional theory calculations.

Visible-light driven photocatalysts are of great importance in wastewater treatment. In this work, fluorine and nitrogen co-doped titanium dioxide/silica nanocomposite (F-N-TiO2/SiO2) was synthetized using a sol-gel approach. The as-developed nanocomposite was well characterized using different techniques. In particular, an anatase structure with high surface area (345.69 m2/g) and a band gap of 2.97 eV were observed for the as-synthesized nanocomposite, which makes it a potential candidate for photocatalytic applications under visible light. A systematic density functional theory calculation was performed to get more insight into the effect of dopant atoms on the band gap of TiO2 nanoparticles. To enhance the reusability of the photocatalyst in semi-pilot scale, the as-developed nanocomposite was immobilized onto the glass beads by coupling dip-coating and heat attachment methods. A semi-pilot scale custom-designed fixed-bed photoreactor was used to evaluate the photocatalytic performance of the as-developed nanocomposite under both visible and solar irradiations. A mixture of three azo dyes (i.e., basic red 29, basic blue 41 and basic yellow 51) was used as the model industrial wastewater. The analysis of the wastewater showed that the complete removal of the pollutants under visible light and sunlight can occurred at pH of 3 and flow rate of 280 mL/min. The durability results demonstrated the successful degradation of the pollutants for five cycles. The results of this study show how careful controlling the operational parameters as well as using a highly photocatalytic nanomaterial can lead to successful decontamination of organic water pollutants. This approach might open up new windows to the future applications of photocatalytic nanomaterials for wastewater treatment.

Purified compounds from marine organism sea pen induce apoptosis in human breast cancer cell MDA-MB-231 and cervical cancer cell Hela.

Marine organisms are an important source of chemical compounds which are appropriate for use as therapeutic agents. Among them, Sea pens produce valuable chemical compounds being used as anti-cancer drugs. The aim of this study was to investigate anti-cancer property of extracted and purified compounds from marine organism Sea pen and evaluate their effects on inducing of apoptosis. The extracts were prepared from dried colony of Virgularia gustaviana. The compounds (3ß)-Cholest,5en,3ol (cholesterol) (15 mg), Hexadecanoic acid (2.5 mg) and 2-Hexadecanol (10.7 mg) were identified by GC-MS and NMR. The cytotoxic effects of the compounds were evaluated on Hela and MDA-Mb-231 human cancer cell lines with MTT assay. Immunocytochemistry and Western Blot analyses were used to evaluate the expression of apoptosis related markers Caspase 3, Caspase 8, Bax and BCL2 in cancer cells after treating with three compounds. The purified compounds reduced viability of human breast cancer cell line MDA-MB-231 and human cervical cancer cell line Hela concentration-dependently. 2-Hexadecanol reduced significantly the viability of both cancer cell lines in comparison to the other purified compounds. Treatment of cancer cells with the three purified compounds increased the expression of caspase-3, caspase-8 and Bax proteins and decreased the relative Bcl-2/Bax ratio, demonstrating induction of apoptosis as possible mechanism of action. According to the results, three purified compounds inhibit the growth of cancer cells by inducing of apoptosis pathway; an effect which needs to be further investigated in the future studies.

Synthesis of N-doped TiO2/SiO2/Fe3O4 magnetic nanocomposites as a novel purple LED illumination-driven photocatalyst for photocatalytic and photoelectrocatalytic degradation of naproxen: optimization and different scavenger agents study.

N-doped TiO2/SiO2/Fe3O4 as a new magnetic photocatalyst that is active in visible light has been prepared by simple sol-gel method. The prepared samples were characterized by XRD, FESEM, EDX, TEM, BET, BJH, VSM, XPS, FT-IR, and DRS-UV/Vis analysis. The photocatalytic effect of synthesized samples on naproxen degradation was studied. The operational parameters were optimized through central composite design to achieve maximum efficiency. The optimum values for maximum efficiency were obtained at pH of 4.29, catalyst mass of 0.06 g, naproxen concentration of 9.33 mg L-1, and irradiation time of 217.06 min. At these optimum conditions, the maximum photocatalytic degradation percentages of naproxen were found to be 96.32% at desirability function value of 1.0. Coupling the electrical current with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the naproxen from aqueous solutions. The photocatalytic activity of the nanoparticles was also studied under sunlight. Considering the results provided by UV-Vis spectrophotometry and total organic carbon, it was found that the prepared samples are extraordinarily efficient to degrade naproxen under both purple LED and solar lights. Furthermore, the effect of different scavenger agents on naproxen degradation has been studied.

Salt-assisted liquid-liquid extraction in microchannel.

In this study, for the first time, salt-assisted liquid-liquid extraction was performed in a microchannel system. The proposed design is based on the increase of contact surface area between target analytes and extracting phase during the sample and extracting phase transfer in microchannel. In this method, first sample solution, extracting solvent, and salt were mixed by stirrer and simultaneously delivered into a microchannel using a syringe pump. In order to optimize the influential parameters on the extraction efficiency of the proposed method, zidovudine and tenofovir disoproxil fumarate were selected as model analytes. The main parameters such as extracting solvent and its volume, salt amount, pH of sample solution, and microchannel shape, length, and its inner diameter were investigated and optimized. Under the optimized conditions, the proposed method was linear in the range of 0.1-30 µg/mL and R2 coefficients were equal to 0.9922 and 0.9947 for zidovudine and tenofovir disoproxil fumarate, respectively. Extraction efficiency of the proposed method was compared with conventional salt-assisted liquid-liquid extraction. The results show that the proposed design has higher extraction efficiency than conventional salt-assisted liquid-liquid extraction. Finally, the proposed method was successfully applied for the determination of zidovudine and tenofovir disoproxil fumarate in plasma samples.

A simple and effective synthesis of magnetic γ-Fe2O3@SiO2@TiO2-Ag microspheres as a recyclable photocatalyst: dye degradation and antibacterial potential.

PURPOSE AND METHODS: In this study, an effective technique for synthesizing γ-Fe2O3@SiO2@TiO2-Ag magnetically separable photocatalyst was introduced by combining co-precipitation, sol-gel, and photo-deposition methods. A series of analyses including FTIR, SEM, EDS, XRD, and VSM were applied to characterize the prepared materials and the investigations on photocatalytic activity of the prepared composites were accomplished. RESULTS: Compared to bare γ-Fe2O3@SiO2@TiO2, the Ag-doped composite was more active in terms of photocatalytic characteristics. By applying γ-Fe2O3@SiO2@TiO2-Ag, the decomposition rate of the Basic blue 41 reached to about 94% after 3 h of UV irradiation; this rate was 63% for pure γ-Fe2O3@SiO2@TiO2. The results indicated that the dye degradation kinetics followed first-order kinetic model. During the five cycles of separation, it was observed that the Ag-doped composite was greatly effective and stable in terms of recycling. Moreover, the results indicated that antibacterial activity of γ-Fe2O3@SiO2@TiO2-Ag was remarkably stronger than that of pure Fe2O3@SiO2@TiO2 particles. CONCLUSION: It was concluded that by modifying magnetic TiO2 by silver nanoparticles, charge separation was eased by catching photo-generated electrons, resulted in an enhanced photo- and biological activity. Graphical abstract.

Inducing Apoptosis of Cancer Cells Using Sea Pen Virgularia gustaviana Extract Which is Comparable to Cembrane Diterpene Sarcophine.

Marine Soft corals have frequently been studied in recent years because of their specific chemical compounds in tissue engineering and regenerative medicine. The aim of this study was to investigate anti-cancer property of extracted compound from Virgularia gustaviana and their effect on inducing of apoptosis. The extraction process was carried out with ethyl acetate for 5 days and the extract was separated by silica-gel column chromatography. The column was washed with n-hexane-ethyl acetate solvent at ratio of 10:0 to 0:10. Thin layer chromatography (TLC), High performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC), and 13C NMR spectroscopy were used for qualitative identification of compounds. The viability of HeLa and MDA-MB-231 cancer cells was investigated using MTT assay at the concentrations of 25, 50, and 100 µL/mL of extracted compounds. Immunocytochemistry and Western Blot analyses were used to evaluate expression of apoptotic markers caspase-3 and caspase-8 in cancer cells after treating with effective fractions (based on viability of cancer cells) and the results were compared with Sarcophine. From ten isolated fractions (A-J), Retention time and Retention Factors (Rf) of fractions G, I, and J were the same as Sarcophine. Fraction G, I, and J dose-dependently decreased cancer cell viability compared to control group and Sarcophine. Treatment of cancer cells with the latest fraction increased expression of caspase-3 and caspase-8 demonstrating induction of apoptosis as possible mechanism of action. According to the results, the compounds extracted from Virgularia gustaviana inhibit the growth of cancer cells by inducing of apoptosis pathway; an effect which needs to be further investigated in the future studies.

Effect of ultrafiltered milk permeate and non-dairy creamer powder concentration on low phenylalanine yoghurt's physicochemical properties during storage.

Phenylketonuria (PKU) is a genetic disorder that has no cure and all patients with this disorder must adhere to a special diet to prevent the onset of symptoms and mental retardation in children. In this study, analog yoghurt with good and acceptable nutrition benefit for PKU patients was produced. Accordingly, ultrafiltered milk permeate was added at two different concentrations of 4 and 5 w/w % and non-dairy creamer at two different concentrations of 1.5 and 2 w/w %. Subsequently, pH, acidity, protein, fat, dry matter, humidity, syneresis and Phe of the yogurts were determined. Protein content, dry matter, pH, acidity and Phe in the analog yogurt with 5 % permeate and 2 % non-dairy creamer were higher than other yoghurt samples, significantly (P < 0.05). During the storage, pH and syneresis of samples reduced, while acidity significantly increased. Phe content of analog yoghurt was low (274 mg/kg).

Zinc and copper concentrations in human milk and infant formulas.

OBJECTIVE: Available accurate data on the concentrations of copper (Cu) and zinc (Zn) in human milk throughout lactation and infant formulas is important both for formulating nutritional requirements for substances and to provide a base line for the understanding the physiology of their secretion. The objective of this study was to analyze the concentrations of zinc and copper in infant formulas and human milk during prolonged lactation. Levels of these metals were examined in relation to selected parameters such as age, weight, height, education and occupation of mothers. METHODS: Thirty mothers referred to the selected clinics in Tehran entered the study. Human milk samples were collected at 2 months postpartum. Zinc and copper concentrations were determined by atomic absorption spectrophotometer. FINDINGS: The mean values of Zn and Cu in human milk were 2.95±0.77mg/L and 0.36±0.11 mg/L. The mean values of Zn and Cu in infant formulas were 3.98±0.25 mg/L and 0.53±0.17mg/L. CONCLUSION: No significant relationship was found between levels of trace elements in human milk and evaluated parameters such as age, weight, height, education and occupation of mothers. The concentrations of zinc and copper in breast milk were lower than those reported in the literature.

Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction.

An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 mug g(-1) and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%.