Facilitation of infectious and non-infectious wound healing using Morus nigra fruit extract ointment: An in vitro and in vivo study.

Accelerating wound healing, as well as preventing infection and scar formation are among the most important medical challenges. This study aims to examine the antimicrobial, immunomodulatory, and anticancer properties of Morus nigra. The antimicrobial activities of ripe and unripe M. nigra fruit (MNF) extracts were tested. HPLC was employed to measure the components in the extract. Oserin ointment was made with 8 % extract. To test the ointment, 48 Wistar rats were randomly assigned into eight groups. The ointment was used daily by treating the wounds. Tissue histology and wound healing were assessed over nine days. Comparative evaluation of wound healing was conducted by analyzing TGF-ß, TNF-α, and IL-1 mRNA levels. Finally, cytotoxic effects on AGS cancer and NIH-3 T3 fibroblast cells were examined. The ANOVA test and Prsim program were used for statistical analysis. Unripe MNF extract had good antimicrobial properties in standard and nosocomial strains. The most abundant compound in the extract was ascorbic acid (0.0441 mg/10 mg extract), followed by naringenin and gallic acid. In all groups treated with MNF extract ointment, a significant reduction in wound area was observed compared to other groups (p < 0.05). After six days of treatment, the microbial load was uncountable. In the microscopic studies of the wounds, a significant increase was observed in fibroblasts, angiogenesis, and in neutrophils in the first days as well as a decrease in the final days. The treatment caused a significant decline in the expression of IL-1 and TNF-α genes, as well as an increase in the expression of TGF-ß (p < 0.05). This extract had no significant cytotoxic effects on human fibroblast cells (p > 0.05). In general, it can be concluded that the unripe MNF extract ointment can be a suitable option for the treatment of infectious and non-infectious skin wounds.

Recent Advances in Catalytic Systems for the Reduction of Aromatic and Aliphatic Nitrile Compounds to Amines.

Amines are important and valuable compounds widely used in the chemical industry to produce various products such as dyes, detergents, solvents, additives, pharmaceutical products, and anti-foam agents. A property that distinguishes primary amines from other compounds is their straightforward functionalization. Therefore, the synthesis of different amine compounds has been considered by many researchers in recent years. Usually, primary amines are produced via amination of alcohols, reductive amination, and reduction of nitro and amide compounds. Furthermore, a useful and atom-economical method for producing primary amines is reducing nitrile compounds using catalytic systems. Traditionally, nitriles are reduced using metal hydrides such as LiAlH4 or NaBH4. These methods have important restrictions in terms of selectivity and waste generation. Hence, the heterogeneous and homogeneous catalysts were investigated for the hydrogenation of nitriles to diverse amines. This review describes the performance of different catalytic systems for reducing nitrile compounds to their corresponding amines.

Cysteine-coated Magnetite Nanoparticles for the Removal of Carmoisine Edible Dye from Aqueous Medium.

BACKGROUND: In this study, cysteine-coated magnetite nanoparticles (Fe3O4@Cys MNPs) were synthesized by chemical method and applied as a recoverable and efficient adsorbent for the removal of carmoisine dye from aqueous solutions. The synthesized MNPs were characterized by FT-IR, XRD, SEM, and TEM studies. METHODS: The effect of various experimental parameters on the dye removal efficiency was studied using Taguchi orthogonal array design (L16 array). Under the optimum conditions (pH = 2, stirring time = 30 min, adsorbent amount = 0.1 g and without salt addition), more than 92% of carmoisine was removed from the aqueous solutions. RESULTS: The kinetic studies showed rapid adsorption dynamics by a pseudo-second-order kinetic model, confirming that diffusion controls the adsorption process. Dye adsorption equilibrium data were fitted well to the Freundlich isotherm, and the synthesized adsorbent showed high removal efficiency. CONCLUSION: The obtained results showed that the synthesized MNPs act as a reusable adsorbent for carmoisine removal with an easy procedure.

The danger of the toxicity and inefficacy of alcohol-based hand rubs in Iran during COVID-19: a cross-sectional study.

BACKGROUND: The use of disinfectants and alcohol-based hand rubs (ABHR) to prevent COVID-19 transmission increased in the first wave of the infection. To meet the increased demand, the Iranian Ministry of Health issued an emergency use authorization allowing new manufacturers to enter the market, despite the limited capacity for surveillance of these products during COVID-19. Methanol poisoning outbreaks spread rapidly, and more people died from methanol poisoning than COVID-19 in some cities. The aim of this study was to analyze some ABHRs in the Iranian market to see if (a) ABHRs are standard and suitable for hand antisepsis and (b) contained potentially dangerous toxic alcohols. METHOD: Between February and March 2020, 64 brands of ABHR were conveniently collected from pharmacies, supermarkets, and shops selling hygienic products and analyzed using Gas Chromatography. World Health Organization and Food and Drug Administration guidelines were used to define minimum requirements for ABHR. For estimating the risk for acute methanol poisoning, we assumed a serum methanol concentration of 200 mg/L following ABHR ingestion was sufficient to cause intoxication. This threshold concentration would be achieved in an average 75-kg adult after consuming 8000 mg (or eight grams) methanol in 1-2 h. RESULTS: The median [IQR] (range) concentration of ethanol, isopropanol, and methanol were 59% v/v [32.2, 68] (0, 99), 0 mg/L [0, 0] (0, 197,961), and 0 mg/L [0, 0] (0, 680,100), respectively. There was a strong negative correlation between methanol and ethanol contents of hand rubbers (r= -0.617, p < 0.001). Almost 47% of ABHRs complied with minimum standards. In 12.5% of ABHRs, high concentrations of methanol were observed, which have no antiseptic properties but could cause acute methanol poisoning if ingested. CONCLUSION: COVID-19 initiated a policy for distribution and use of ABHR with little control. As ABHR and masks are still accepted preventive measures of the disease, non-standard ABHR compositions may increase the population's risk to both COVID-19 infection and methanol poisoning.

Magnetite azolla impedimetric nanobiosensor for phthalic acid esters quantification.

Phthalic acid esters (PAEs) are a group of organic compounds that show vulnerability effects in different stages of human development. In this work, two sensitive and efficient impedimetric biosensors (IBs) were introduced and their interactions with four PAEs, namely dibutyl phthalate (DBP), dimethyl phthalate (DMP), di(2-ethylhexyl) phthalate (DEHP), and dicyclohexyl phthalate (DCHP), in aqueous solutions with these biosensors were separately investigated via electrochemical impedance spectroscopy (EIS). The surface of a copper electrode was modified by azolla fern dried powder (AZ) and magnetite-modified azolla nanocomposites (MAZ NCs) to form an azolla-based impedimetric biosensor (AZIB) and magnetite azolla nanocomposite-based impedimetric nanobiosensor (MAZIB), respectively. Determinations of PAEs with the designed biosensors were conducted based on their blocking effect on the biosensor surface to ferrous ions oxidation. After each impedimetric measurement, the electrode surface was covered again with the modifier. Nyquist plots were obtained and indicated that the charge-transfer resistance (RCT) values of the bare electrode, AZIB, and MAZIB without injection of PAEs were 468.8, 438.7, and 285.1 kΩ, respectively. After the separate injection of DBP, DMP, DEHP, and DCHP (3 µg L-1) on the surface of AZIB and MAZIB, RCT values were obtained as 563.9, 588.5, 548.7, and 570.1 kΩ for AZIB and 878.2, 1219.2, 754.3, and 814.7 kΩ for MAZIB, respectively. It was observed that the PAE blockers with a smaller structure provided better point-by-point coverage of the surface, which led to a bigger shift in RCT. The linear relationship between the EIS responses and each PAE concentration was investigated in the range of 0.1-1000 µg L-1. The limit of detection (LOD) and limit of quantification (LOQ) values were obtained in the ranges of 0.003-0.005 µg L-1 and 0.010-0.016 µg L-1 for AZIB and 0.008-0.009 µg L-1 and 0.027-0.031 µg L-1 for MAZIB, respectively. The results showed that these biosensors can be used to determine PAEs in real aqueous samples with good relative recoveries ranging from 93.0-97.7% (RSD < 2.58%) for AZIB and 93.3-99.3% (RSD < 2.45%) for MAZIB. The results confirmed that these impedimetric biosensors offer high sensitivity and performance for the determination of trace PAEs in aqueous samples.

Selective aptamer conjugation to silver-coated magnetite nanoparticles for magnetic solid-phase extraction of trace amounts of Pb2+ ions.

Herein, a novel aptamer-functionalized magnetic adsorbent was developed and combined with magnetic solid-phase extraction (MSPE) for the specific enrichment of Pb2+ ions prior to flame atomic absorption spectrometric detection. First, silver-coated magnetite core-shell nanoparticles (Fe3O4@Ag MNPs) were synthesized by the chemical reduction of silver ions on the surface of magnetite nanoparticles. After that, the selective DNA aptamer against Pb2+ was conjugated on the surface of the synthesized nanoparticles to form aptamer-modified magnetic nanoparticles (Fe3O4@Ag-APT). The characterization of the prepared adsorbent was performed through SEM imaging, XRD, FT-IR, EDX, and DRS instruments. The influence of the various experimental parameters on the adsorption and desorption steps in MSPE was investigated via Taguchi experimental design to optimize different parameters. Under the optimized conditions, the Pb2+ calibration graph was linear in the range of 33-1000 µg L-1. The relative standard deviation (RSD%) of the method for six replicates containing 100 µg L-1 of Pb2+ ions was 0.34%. Furthermore, the limit of detection (LOD) and the limit of quantification (LOQ) were 10 µg L-1 and 33.3 µg L-1, respectively. Finally, the applicability of the proposed method was successfully confirmed by preconcentration and determination of trace amounts of Pb2+ ions in tap and seawater samples. We showed a proof of concept for Fe3O4@Ag-APT as an efficient bio-adsorbent, offering a promising strategy for the specific binding/removal of toxic heavy metal ions.

Surface blocking of azolla modified copper electrode for trace determination of phthalic acid esters as the molecular barricades by differential pulse voltammetry: response surface modelling optimized biosensor.

In this work, a sensitive and efficient voltammetric biosensor was introduced for differential pulse voltammetric (DPV) determination of some phthalic acid esters (PAEs) including dibutyl phthalate (DBP), dimethyl phthalate (DMP), di(2-ethylhexyl)phthalate (DEHP) and dicyclohexyl phthalate (DCHP) in aqueous solutions. Briefly, the surface of a copper electrode was modified by azolla paste prepared using azolla powder and electroencephalography gel (EEG). The modified surface was characterized by electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) analysis and energy dispersive X-ray (EDX) methods. Determination of PAEs was conducted based on their blocking effect on the electrode surface for ferrous ion oxidation. The central composite design (CCD) was conducted to optimize the effects of four experimental parameters including the concentration of Fe2+ ions (C Fe2+ ) and supporting electrolyte (C sup. elec), solution pH and modifier/gel mass ratio on the decrease in the anodic peak current of ferrous ions as the response. Predicted optimal conditions (C Fe2+ = 319 µM, C sup. elec= 0.125 M, pH = 7.52 and modifier/gel mass ratio = 0.19) were validated by experimental checking which resulted in an error of 1.453%. At the optimum conditions, linear relationships were found between the DPV responses and PAEs concentrations and the limit of detection (LOD) and limit of quantification (LOQ) values were in the ranges of 0.2-0.4 µg L-1 and 0.5-1.0 µg L-1, respectively. Good recovery percentages ranging from 97.3 to 100.3% with RSD < 3.2% suggested the proposed method for efficient, accurate and quick determination of PAEs in real water samples.

Synthesis of Kit-6 Magnetite Silica Nanocomposite Functionalized by Amine Group for Removal of Carmoisine Dye from Aqueous Solutions.

OBJECTIVE: In this study, amine-functionalized magnetite Kit-6 silica nanocomposite (Fe3O4@SiO2@Kit-6-NH2) was synthesized as an adsorbent for removing Carmoisine food dye from aqueous solutions. METHODS: The nanocomposite was chemically synthesized and was characterized by X-ray diffraction analysis (XRD), vibrating sample magnetometery (VSM), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Taguchi orthogonal array experimental design method was used to optimize the experimental conditions, including adsorbent amount, pH of the solution, amount of salt, the volume of sample and contact time. Pseudo first-order, pseudo second-order, intra-particle diffusion and Elovich kinetic models were investigated to study the kinetic parameters of the sorption process. RESULTS: The kinetic data corresponded to the pseudo second-order kinetic model with R2 = 0.9999. Also, adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R2 = 0.9984, n=1.0786). The reusability tests showed that the proposed nanocomposite could be used for more than 8 cycles with removal efficiency higher than 90%. CONCLUSION: The applicability study of the proposed nanocomposite proved its ability for efficient removal of Carmoisine dye from real aqueous samples.

Chemoselective reduction of nitro and nitrile compounds using an Fe3O4-MWCNTs@PEI-Ag nanocomposite as a reusable catalyst.

Multi-walled carbon nanotubes (MWNTs) were modified with carboxylic acid functional groups (MWCNTs-(COOH) n ) prior to decoration with Fe3O4 nanoparticles. A further modification step by polyethyleneimine (PEI) resulted in Fe3O4-MWCNTs@PEI which provided a suitable platform for coordination and in situ reduction of silver ions to obtain an Fe3O4-MWCNTs@PEI-Ag nanocomposite with highly dispersed Ag nanoparticles. The Fe3O4-MWCNTs@PEI-Ag hybrid material was characterized by various techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA), and was used as an efficient catalyst for chemoselective reduction of nitroaromatic and nitrile compounds to their corresponding amines in aqueous solution at ambient temperature. Nitrofurazone, a cytotoxic antibiotic, as a non-aromatic example was also reduced selectively at the nitro group without reduction of the other functionalities in the presence of Fe3O4-MWCNTs@PEI-Ag. The catalyst was magnetically recoverable and maintained its activity for at least six cycles without considerable loss of efficiency.

Evaluation of methanol content of illegal beverages using GC and an easier modified Chromotropic acid method; a cross sectional study.

BACKGROUND: Methanol is highly toxic to human beings and naturally exists in some beverages. Having access to an easy and cheap method for its determination is of great importance to increase the safety of use of these beverages. Our main aim is to evaluate methanol concentration of some alcoholic beverages in Iran black market and compare it with the European and US standards. Also, we evaluated the efficacy of a newly designed and produced chemical kit in determining the risk of methanol toxicity by drinking of such samples compared to gas chromatography method. METHODS: Methanol content of suspected alcoholic beverages referred to forensic toxicology laboratory, Guilan province, Iran was measured using gas chromatography and a recently designed kit based on modified colorimetric chromotropic acid method. RESULTS: Of 1221 samples, 145 (11.9%) had no ethanol content, while in three samples (0.25%), methanol was high enough (700,000; 870,000; 920,000 mg/L) to cause severe methanol toxicity. Median [IQR] ethanol content of the suspected samples was 9% [3.7, 32.75]. Methanol was detected in 128 (10.48%) samples using gas chromatography method and 160 samples (13.1%) with designed kit with 100% sensitivity, 97.07% specificity, and 100% negative-predictive-value. CONCLUSIONS: Alcoholic beverages produced in local black market in Iran are not safe at all. The application of the new method is practical, rapid, easy, and accurate to evaluate the risk of methanol toxicity in suspected alcoholic drinks.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye.

OBJECTIVE: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. METHOD: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. RESULTS: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). CONCLUSION: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

Solid phase extraction of Cu2+, Ni2+, and Co2+ ions by a new magnetic nano-composite: excellent reactivity combined with facile extraction and determination.

In the present study, silica magnetite mesoporous nanoparticles functionalized with a new chelating agent were synthesized and introduced as a magnetic solid phase for preconcentration of trace amounts of Cu2+, Ni2+, and Co2+ ions from aqueous solutions. Briefly, MCM-41 mesoporous-coated magnetite nano-particles (MMNPs) with particle size lower than 15 nm were synthesized via chemical co-precipitation methods. Then, N-(4-methoxysalicylidene)-4,5-dinitro-1,2-phenylenediamine (HL) as a new chelating agent was synthesized and used for surface modification of mesoporous magnetic solid phase by dispersive liquid-liquid functionalization (DLLF) as a new rapid method to form HL functionalized mesoporous magnetite nanoparticles (MMNPs─HL). The structure and morphology of prepared sorbent were characterized by FT-IR, XRD, VSM, and TEM. Finally, the prepared nanoparticles were utilized for preconcentration of Cu2+, Ni2+, and Co2+ ions prior to determination by atomic absorption spectrophotometery. The calibration graph was obtained under the optimized conditions with linear dynamic range of 1.0-300 µg L(-1) and correlation coefficient (r2) of 0.998. The detection limits of this method for cobalt, nickel, and copper ions were 0.03, 0.03, and 0.04 ng/mL, respectively. Finally, the method was successfully applied to the extraction and determination of the analyte ions in natural waters and reference plant samples.

Nano magnetic solid phase extraction for preconcentration of lead ions in environmental samples by a newly synthesized reagent.

In this study, magnetite nanoparticles with particle size lower than 47 nm were synthesized and were applied for preconcentration of Pb2+ ions from aqueous solutions. To preconcentrate the Pb2+ ions, the surface of the synthesized nano particles was modified with sodium dodecyl sulfate (SDS) as an anionic surfactant. A new chelating agent (2-((E)-2-amino-4,5-dinitrophenylimino)methyl)phenol) was synthesized and used to form a very stable complex with Pb2+ ions. The lead ions formed complexes and were quantitatively extracted with SDS-coated magnetite nanoparticles. After magnetic separation of adsorbent, the adsorbent was eluted with 0.5% (v/v) HC1 in dimethyl sulfoxide (DMSO) prior to analysis by flame atomic absorption spectrometry (FAAS). Orthogonal array design (OAD) was used to study and optimize the different experimental parameters. Under the optimum conditions, enhancement factor up to 63.5 was achieved for extraction from only 10 mL of sample solution and the relative standard deviation (RSD %) of the method was lower than 2.8%. The obtained calibration curve was linear in the range of 1-300 pg L-' with reasonable linearity (r2 > 0.998). The limit of detection (LOD) based on S/N = 3 was 0.04 microg L(-1) for 10 mL sample volumes. Finally, applicability of the proposed method was successfully confirmed by preconcentration and determination of trace amounts of lead ions in environmental samples and satisfactory results were obtained.

Linear and non-linear quantitative structure-activity relationship models on indole substitution patterns as inhibitors of HIV-1 attachment.

The antiviral drugs that inhibit human immunodeficiency virus (HIV) entry to the target cells are already in different phases of clinical trials. They prevent viral entry and have a highly specific mechanism of action with a low toxicity profile. Few QSAR studies have been performed on this group of inhibitors. This study was performed to develop a quantitative structure-activity relationship (QSAR) model of the biological activity of indole glyoxamide derivatives as inhibitors of the interaction between HIV glycoprotein gp120 and host cell CD4 receptors. Forty different indole glyoxamide derivatives were selected as a sample set and geometrically optimized using Gaussian 98W. Different combinations of multiple linear regression (MLR), genetic algorithms (GA) and artificial neural networks (ANN) were then utilized to construct the QSAR models. These models were also utilized to select the most efficient subsets of descriptors in a cross-validation procedure for non-linear log (1/EC50) prediction. The results that were obtained using GA-ANN were compared with MLR-MLR and MLR-ANN models. A high predictive ability was observed for the MLR, MLR-ANN and GA-ANN models, with root mean sum square errors (RMSE) of 0.99, 0.91 and 0.67, respectively (N = 40). In summary, machine learning methods were highly effective in designing QSAR models when compared to statistical method.

Ionic liquid-based dispersive liquid-liquid microextraction for the determination of formaldehyde in wastewaters and detergents.

Spectrophotometry in combination with ionic liquid-based dispersive liquid-liquid microextraction (DLLME) was applied for the extraction and determination of formaldehyde in real samples. The method is based on the reaction of formaldehyde with methyl acetoacetate in the presence of ammonia. The variation in the absorbance of the reaction product was measured at 375 nm. An appropriate mixture of ethanol (disperser solvent) and ionic liquid, 1-hexyl-3-methylimidazoliumhexafluoro-phosphate [C(6)MIM][PF(6)] (extraction solvent) was rapidly injected into a water sample containing formaldehyde. After extraction, sedimented phase was analyzed by spectrophotometry. Under the optimum conditions, the calibration graph was linear in the range of 0.1-20 ng mL(-1) with the detection limit of 0.02 ng mL(-1) and limit of quantification of 0.08 ng mL(-1) for formaldehyde. The relative standard deviation (RSD%, n = 5) for the extraction and determination of 0.8 ng mL(-1) of formaldehyde in the aqueous samples was 2.5%. The results showed that DLLME is a very simple, rapid, sensitive, and efficient analytical method for the determination of trace amounts of formaldehyde in wastewaters and detergents, and suitable results were obtained.

Review on methods for determination of metallothioneins in aquatic organisms.

One aspect of environmental degradation in coastal areas is pollution from toxic metals, which are persistent and are bioaccumulated by marine organisms, with serious public health implications. A conventional monitoring system of environmental metal pollution includes measuring the level of selected metals in the whole organism or in respective organs. However, measuring only the metal content in particular organs does not give information about its effect at the subcellular level. Therefore, the evaluation of biochemical biomarker metallothionein may be useful in assessing metal exposure and the prediction of potential detrimental effects induced by metal contamination. There are some methods for the determination of metallothioneins including spectrophotometric method, electrochemical methods, chromatography, saturation-based methods, immunological methods, electrophoresis, and RT-PCR. In this paper, different methods are discussed briefly and the comparison between them will be presented.

A Fast Response Membrane Sensor based on Ethyl 1, 2, 3, 4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate for Detection of Lanthanum (III) Ions at Wide Concentration Range.

A PVC membrane La (III) ion-selective electrode has been constructed using ethyl1,2,3,4-tetrahydro-6-methyl-4-phenyl-2-thioxopyrimidine-5-carboxylate (ETMPTC) as a neutral ionophore. This electrode responds to La (III) ion with a sensitivity of 19.9 ± 0.3 mV/decade over the range 9.3 × 10-8 to 1.0 × 10-1 M at pH 3.0-10.0. The limit of detection was 1.7 × 10-8 M. It has a response time of < 11s and can be used for at least 3 months without any divergence in potentials. The proposed electrode shows fairly good discrimination of La (III) ion from several cations. The effect of organic solvents on electrode response was examined. The results show that this electrode can be used in ethanol media until 20% (v/v) concentration without interference. The isothermal temperature coefficient of this electrode amounted to 0.00013 V/ °C. This sensor not only was used as an indicator electrode in potentiometric titration of lanthanum ion against EDTA but also was used to determination of La3+ concentration in the presence of certain interfering ions.

Dispersive liquid-liquid microextraction of copper ions as neocuproine complex in environmental aqueous samples.

In the present study, a simple and efficient extraction method based on dispersive liquid-liquid microextraction prior to UV-Vis spectrophotometry was developed for the preconcentration and determination of copper ions in environmental samples. Briefly, cupric ions (Cu II) were reduced to cuprous (Cu I) with addition of hydroxyl amine hydrochloride and formed hydrophobic chelates with neocuproine. Then, a proper mixture of acetonitrile (as dispersive solvent) and choloroform (as extraction solvent) was rapidly injected into the solution and a cloudy solution was formed. After centrifuging, choloroform was sedimented at the bottom of a conical tube and diluted with 100 µL of methanol for further UV-Vis spectrophotometry measurement. An orthogonal array design (OAD) was employed to study the effects of different parameters on the extraction efficiency. Under the optimum experimental conditions, a preconcentration factor up to 63.6 was achieved for extraction from 5.0 mL of sample solution. The limit of detection (LOD) based on S/N = 3 was 0.33 µg L-1 and the calibration curve was linear in the range of 1-200 µg L-1 with reasonable linearity (r2 > 0.997). Finally, the accuracy of the proposed method was successfully evaluated by determination of trace amounts of copper ions in different water samples and satisfactory results were obtained.

Comparison of solidification of floating drop and homogenous liquid-liquid microextractions for the extraction of two plasticizers from the water kept in PET-bottles.

Two approaches based on solidification of floating drop microextraction (SFDME) and homogenous liquid-liquid microextraction (HLLE) were compared for the extraction and preconcentration of di-(2-ethylhexyl) phthalate (DEHP) and di-(2-ethylhexyl) adipate (DEHA) from the mineral water samples. In SFDME, a floated drop of the mixture of acetophenone/1-undecanol (1:8) was exposed on the surface of the aqueous solution and extraction was permitted to occur. In HLLE, a homogenous ternary solvent system was used by water/methanol/chloroform and the phase separation phenomenon occurred by salt addition. Under the optimal conditions, the LODs for the two target plasticizers (DEHA and DEHP), obtained by SFDME-GC-FID and HLLE-GC-FID, were ranged from 0.03 to 0.01 microg/L and 0.02 to 0.01 microg/L, respectively. HLLE provided higher preconcentration factors (472.5- and 551.2-fold) within the shorter extraction time as well as better RSDs (4.5-6.9%). While, in SFDME, high preconcentration factors in the range of 162-198 and good RSDs in the range of 5.2-9.6% were obtained. Both methods were applied for the analysis of two plasticizers in different water samples and two target plasticizers were found in the bottled mineral water after the expiring time and the boiling water was exposed to a polyethylene vial.