Bioengineered synthesis of phytochemical-adorned green silver oxide (Ag2O) nanoparticles via Mentha pulegium and Ficus carica extracts with high antioxidant, antibacterial, and antifungal activities.

Silver oxide nanoparticles have various biomedical and pharmaceutical applications. However, conventional nanofabrication of Ag2O is associated with the use of toxic chemicals and organic solvents. To circumvent this hurdle, herein silver oxide quantum dots (Ag2O-QDs) were synthesized quickly (3 min) via the use of ultrasonic irradiation and plant-extract. Additionally, due to ultrasonic irradiation's effect on cell-wall destruction and augmentation of extraction efficiency, ultrasonic was also used in the preparation of Mentha pulegium and Ficus carica extracts (10 min, r.t) as natural eco-friendly reducing/capping agents. The UV-Vis result indicated a broad absorption peak at 400-500 nm. TEM/SEM analysis showed that ultrasound introduced a uniform spherical particle and significantly reduced particle size compared to the conventional heating method (∼ 9 nm vs. ∼ 100 nm). Silver and oxygen elements were found in the bio-synthesized Ag2O by EDS. The FTIR and phenol/flavonoid tests revealed the presence of phenol and flavonoid associated with the nanoparticles. Moreover, nanoparticles exhibited antioxidant/antibacterial/antifungal activities. The MIC and MBC results showed the Ag2O QDs synthesized with M. pulegium extract have the highest antibacterial activity against E. coli (MBC = MIC:15.6 ppm), which were significantly different from uncoated nanoparticles (MBC = MIC:500 ppm). The data reflects the role of phyto-synthesized Ag2O-QDs using ultrasonic-irradiation to develop versatile and green biomedical products.

Smartphone-based colorimetric determination of triclosan in aqueoussamples after ultrasound assisted-dispersive liquid-liquid microextraction under optimized response surface method conditions.

In the present study, a simple and low cost methodology based on ultrasonic assisted-dispersive liquid-liquid microextraction (UA-DLLME) followed by smartphone-based colorimetric measurement was introduced for the separation and determination of Triclosan (TCS) from contaminated waters. This method is based on the formation of an azo compound from the alkaline reaction of TCS with a diazonium ion, resulting from the reaction of sodium nitrite and p-sulfanilic acid in an acidic medium. The orange-brown color product was extracted into a low volume of organic phase by UA-DLLME method and RGB values were recorded with free Android app Color Grab. The effective parameters in this procedure, namely solution pH, p-sulfanilic acid and nitrite concentration, reaction time and volume of the extraction solvent were investigated and optimized by response surface methodology (RSM) based on a Box-Behnken design (BBD) model. Under optimum conditions, the calibration graph was linear in the range of 3.0 and 200 µg L-1 of TCS. The limit of detection (LOD) and limit of quantification (LOQ) were 0.8 and 2.7 µg L-1, respectively. The proposed method was successfullyused for the analyses of triclosan in several water and wastewater samples and satisfactory results were obtained.

Trace metal content in annually banded scleractinian coral 'Porites lobata' across the northern Persian Gulf.

Concentrations of trace metals in skeleton growth bands of dominant scleractinian coral 'Porites lobata' in different years were investigated in Kharg and Hebourabi islands in the northern coast of the Persian Gulf. The highest average concentrations of metals respectively were Sr> Mg> Zn> Ba> Cu> U> Ni> Mn> Cr> Co> Pb> V> Cd in Kharg and Sr> Mg> Ba> Cu> U> Ni> Zn> Mn> Cr> Co> V> Pb> Cd in Hendourabi. The coefficient of variation percentages (CV%) of Cr, Mn, Zn, Ba, and Pb in Kharg and Cu and Ba in Hendourabi were more than 50%. Results of PCA analyses revealed that the levels of trace metals in Kharg were defined by three principle components: the first component (Mn, V, Pb, Zn, Ni and half of Mg, Cr and Co) corresponding to the past regional military conflicts and oil pollution, the second component (Sr, U, and Mg) corresponding to sea surface temperature (SST) changes, and the third component (Cr and Co) corresponding to other factors. The results of PCA analyses revealed that trace metals in Hendourabi were defined by two principle components including the first component (Co, Ni, Cr, Mn, and half of Ba) corresponding to annual precipitation changes and the second component (U, Zn, and Ba) corresponding to coastal constructions. The results showed that trace metal contamination in Kharg is higher than those of Hendourabi as a result of the oil exploration-related activities and war.

Assessment of incremental lifetime cancer risks of ambient air PM10-bound PAHs in oil-rich cities of Iran.

This study investigates the concentrations of PM10-bound PAHs and their seasonal variations in three cities of Ahvaz, Abadan, and Asaluyeh in Iran. The mean concentrations of PM10 in two warm and cold seasons in Ahvaz were higher and in Abadan and Assaluyeh were lower than the national standard of Iran and the guidelines of the World Health Organization. The Σ16 PAHs concentration in ambient air PM10 during the cold season in Ahvaz, Abadan and Asaluyeh was 244.6, 633, and 909 ng m- 3, respectively, and during the warm season in Ahvaz, Abadan, and Asaluyeh was 242.1, 1570 and 251 ng m- 3, respectively. The high molecular weight PAHs were the most predominant components. The most abundant PAHs species were Pyr, Chr, B [ghi] P, and Flt. The results showed that the total PAHs concentration in the cold and warm seasons was dependent on industrial activities, particularly the neighboring petrochemical units of the city, vehicular exhausts, traffic and use of oil, gas, and coal in energy production. The total cancer risk values as a result of exposure to PAHs in ambient air PM10 in all three cities for children and adults and in both cold and warm seasons were between 1 × 10- 6 and 1 × 10- 4, and this indicates a potential carcinogenic risk. Therefore, considering the various sources of air pollutants and its role on people's health, decision makers should adopt appropriate policies on air quality to reduce the ambient air PAHs and to mitigate human exposure.

Selenium functionalized magnetic nanocomposite as an effective mercury (II) ion scavenger from environmental water and industrial wastewater samples.

A novel core-shell magnetic-selenium nanocomposite (Fe3O4@SiO2@Se) was synthesized for fast and effective removal of Hg (II) ions from various industrial and environmental water samples. The composition, property, and structure of Fe3O4@SiO2@Se were characterized by spectral and microscopic techniques. The key parameters affecting the removal were evaluated and optimized. The concentration of residual Hg (II) ions in the solution was measured using a cold vapor atomic absorption spectrometer. At pH = 3.0, Fe3O4@SiO2@Se was capable to remove Hg (II) ions ranged from 100 µg L-1 to 10 mg L-1 within 20 min with the efficiency of approximately 99% in a way that residual concentration levels matched international standards. This level of removal efficiency was well maintained up to salinity of 25 g L-1. Kinetic investigations revealed compliance with a second-order kinetic model. The linear regression coefficient suggested the adsorption of Hg (II) ions by the adsorbent followed the Langmuir isotherm model (R2 > 0.997). The maximum capacity of the adsorbent obtained through investigating the isotherms was 70.42 mg g-1. The Fe3O4@SiO2@Se adsorbent effectively removed the Hg (II) ions spiked to different samples, including tap water, river water, seawater, and industrial wastewater. Therefore, this nano-adsorbent can be used as a good alternative for Hg (II) removal, in practical applications.

Applying Al2O3@Ag@trithiocyanuric acid as an efficient metal ion scavenger for the selective extraction of iron (III) and lead (II) from environmental waters.

In the present study, silver (Ag) atoms were chemically deposited on γ-alumina (Al2O3) nanospheres to be further functionalized with trithiocyanuric acid (TTC). The result was Al2O3@Ag@TTC composites, which were used for the selective extraction and preconcentration of Fe (III) and Pb (II) ions in seawater and river water samples. TTC is a potent scavenger of heavy metal ions with multiple nitrogen- and sulfur-containing functional groups. The concentrations of analytes were determined by flame atomic absorption spectrometry, and the structure of the synthetic adsorbent was characterized by spectral and microscopic techniques. Furthermore, the fundamental parameters influencing the extraction and desorption of the target ions were evaluated. Under optimized conditions, the calibration curve was linear in the range of 10-100 ng mL-1 for both analytes. The detection limits of the proposed method for Fe (III) and Pb (II) ions were 1.5 ng mL-1 and 0.8 ng mL-1, respectively, with a relative standard deviation of less than 6.1% (n = 7). Moreover, the proposed method tolerated salinities of up to 50.0 g L-1 without exhibiting any decrease in selectivity or recovery. The developed method was successfully applied to extract Fe (III) and Pb (II) ions from seawater and river water samples. The extraction recovery rates of the spiked ions were at least 93% for Fe (III) and 97 % for Pb (II).

Occurrence, distribution, and risk assessment of bisphenol A in the surface sediments of Musa estuary and its tributaries in the northern end of the Persian Gulf, Iran.

Musa estuary and its tributaries, located northwest of the Persian Gulf, host many industrial complexes, high-density ports, and urban areas along their coastal regions and are, therefore, constantly threatened by chemical contamination. The present study is the first to have investigated the surface sediments in six stations of the Musa estuary tributaries. The mean variations in BPA concentrations in the dry sediments of these stations ranged from 2.22 to 16.71 ng/g. Fairly high levels of BPA were found in Durragh station and its neighboring industrial sites. The lowest BPA level (2.22 ng/g) was observed in the station at the mouth of the Persian Gulf. Based on the EU risk-assessment system, the concentration levels of BPA in the sediments are in the low-risk range. Only in certain areas of the estuary were the sediments of moderate risk, and prolonged contact between ecological populations and them could cause toxicity in aquatic organisms.

Phycosynthesis and Enhanced Photocatalytic Activity of Zinc Oxide Nanoparticles Toward Organosulfur Pollutants.

A novel eco-friendly procedure was developed to produce safer, stable and highly pure zinc oxide nanoparticles (ZnO NPs) using microalgae Chlorella extract. The ZnO NPs were synthesized simply using zinc nitrate and microalgae Chlorella extract which conducted at ambient conditions. In this recipe, microalgae Chlorella extract acted as the reducing agent and a stabilizing layer on fresh ZnO NPs. UV-visible spectrum was confirmed the formation of ZnO NPs showing an absorption peak at 362 nm. XRD results demonstrated that prepared ZnO NPs has a high-crystalline hexagonal (Wurtzite) structure, with average size about 19.44 nm in diameter. FT-IR spectral analysis indicated an active contribution of algae-derived biomolecules in zinc ions bioreduction. According to SEM and TEM observations, ZnO NPs are well dispersed and has a hexagonal shape with the average size of 20 ± 2.2 nm, respectively. Based on gas chromatography analyses, the optimum 0.01 g/L dosage of ZnO catalyst revealed an effective photocatalytic activity toward the degradation (97%) of Dibenzothiophene (DBT) contaminant as an organosulfur model in the neutral pH at the mild condition. Rapid separation and facile recyclability at five consecutive runs were demonstrated high efficiency and durability of green ZnO nanophotocatalyst. The possible mechanisms of green ZnO NPs formation and the photo-desulfurization of DBT were also proposed.

Simultaneous extraction of polycyclic aromatic hydrocarbons through the complete dissolution of solid biological samples in sodium hydroxide/urea/thiourea aqueous solution.

In order to precisely and simultaneously extract polycyclic aromatic hydrocarbons (PAHs) for measurement using a high performance liquid chromatography-fluorescence detector (HPLC-FL), a novel sample preparation method was developed. This method is based on the complete and fast dissolution of biological samples in a new non-alcoholic alkaline medium. A solution composed of NaOH/urea/thiourea at an optimized ratio was used for complete dissolution of approximately 0.25g dried fish samples within 20min. The proposed method was conducted at 10°C and under atmospheric pressure to obtain a stable and highly homogeneous solution, without the need for microwaves or any other apparatus. This process operates at considerably lower temperature than conventional methods and provides an opportunity to simultaneously extract the target analytes from their matrices by adding the extracting solvent in the initial steps of the dissolution; this process greatly reduced the time of analysis and the loss of analytes via vaporization. Several key parameters were identified and their effects on precision and extraction recoveries were investigated. Linearity over a calibration range of 1.0-100 and 2.5-100ngg-1 was achieved, with high coefficients of determination (r2) ranging between 0.9987 and 0.9998. Based on relative standard deviations (n=5), the intra-day and inter-day precisions of the spiked PAHs were found to be better than 3.1% and 3.2%, respectively, at a concentration level of 25ngg-1. The recoveries of PAH from spiked marine fish tissues and shrimp samples were in the range of 90.6%-100.4%. The spiked samples were also treated with the alcoholic alkaline and Soxhlet extraction methods in order to provide a comparison.

Competitive adsorption of phthalate esters on marine surface sediments: kinetic, thermodynamic, and environmental considerations.

In this study, the sorption behavior of six widely used phthalate esters (PEs) on marine sediments was investigated. The adsorption of PEs was fast and reached the equilibrium within 6 h. The forward and backward rate constants of all PEs on sediments were calculated. Several kinds of kinetic and thermodynamic models have been investigated; the pseudo-second-order model and the partition isotherm model were best fitted to the adsorption behavior of PEs. The rate-limiting step of sorption was controlled by the film diffusion mechanism. After treating sediments with H2O2, the partition coefficients of all PEs were significantly reduced and indicated that the amorphous organic carbon has a major role in adsorption process. The negative values of ΔH° and ΔG° for these compounds showed that the sorption process is exothermic and spontaneous. The adsorption capacities of all PEs were slightly influenced by increasing the salinity from 0 to 40 g L-1. These research findings have a prime importance on assessment of the fate and transport of PEs in seawater-sediment systems.

Dissolution of biological samples in deep eutectic solvents: an approach for extraction of polycyclic aromatic hydrocarbons followed by liquid chromatography-fluorescence detection.

A novel sample preparation method based on the complete dissolution of marine biological samples in choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent was developed for fast and efficient extraction of eight polycyclic aromatic hydrocarbons (PAHs) using minimum volumes of cyclohexane. The extracted PAHs were purified and then measured by high-performance liquid chromatography-fluorescence detection (HPLC-FL). The effect of key parameters on extraction recoveries and precision was investigated. At optimized conditions, the studied samples were dissolved under atmospheric pressure in ChCl-Ox (1:2) at 55°C for 30min, which is considerably lower than the temperature used in the classical and current methods. After dissolution, it took approximately 20min to quantitatively extract the PAHs from ChCl-Ox using 5mL cyclohexane. Depending on the analyte, the developed method was linear over the calibration range 1.0-250, 2.0-250, and 5.0-250ngg(-1), with r(2)>0.996. The detection limits of the method were between 0.50 and 3.08ngg(-1). The intra-day and inter-day precisions (based on the relative standard deviation, n=5) of the spiked PAHs at a concentration level of 50ngg(-1) were better than 12.6% and 13.3%, respectively. Individual PAH recoveries from spiked marine fish and macroalgae samples were in the range of 71.6% to 109.6%. For comparison, the spiked samples were also subjected to the Soxhlet extraction method. The simplicity of the procedure, high extraction efficiency, short analysis time, and use of safe and inexpensive components suggest the proposed method has a high potential for utilization in routine trace PAH analysis in biological samples.

Heavy metals' concentration in sediment, shrimp and two fish species from the northwest Persian Gulf.

The concentrations of heavy metals (cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn)) were measured in hepatopancreas and muscle of a commercial shrimp (Metapenaeus affinis), in the muscle, liver and gills of two fish species (Thryssa vitrirostris and Johnius belangerii) and in the sediment samples taken from the mouth of the Arvand river, Meleh estuary and Musa estuary in the northeast Persian Gulf. Concentration of heavy metals varied depending on different tissues, species and sampling sites. Liver of fish and hepatopancreas of shrimp exhibited higher metals' concentration than the other tissues. Generally, in the mouth of the Arvand river, the highest concentration of metals was found in benthic species; while in the mouth of Musa estuary, the highest level of the metals was found in pelagic fish species. Bioaccumulation factors were observed to follow the order: J. belangerii-liver-Cd > T. vitrirostris-liver-Pb > M. affinis-hepatopancreas-Zn >M. affinis-hepatopancreas-Cu >M. affinis- hepatopancreas-Ni. The analysed heavy metals were found in sediment samples at mean concentration in the sediment quality guideline proposed by National Oceanic and Atmospheric Administration (NOAA) and Regional Organization for the Protection of The Marine Environment (ROPME), except for Ni concentration in some cases.

A novel digestion method based on a choline chloride-oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples.

A novel and efficient digestion method based on choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl-Ox (1:2, molar ratio) at 100°C for 45 min. Then, 5.0 mL HNO(3) (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P=0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the use of safe and inexpensive components demonstrate the high potential of ChCl-Ox (1:2) for routine trace metal analysis in biological samples.

Application of sulfur microparticles for solid-phase extraction of polycyclic aromatic hydrocarbons from sea water and wastewater samples.

The application of sulfur microparticles as efficient adsorbents for the solid-phase extraction (SPE) and determination of trace amounts of 10 polycyclic aromatic hydrocarbons (PAHs) was investigated in sea water and wastewater samples using high performance liquid chromatography coupled with an ultraviolet detector (HPLC-UV). Parameters influencing the preconcentration of PAHs such as the amount of sulfur, solution flow rate and volume, elution solvent, type and concentration of organic modifier, and salt effect were examined. The results showed that at a flow rate of 10 mL min(-1) for the sample solutions (100mL), the PAHs could be adsorbed on the sulfur microparticles and then eluted by 2.0 mL of acetonitrile. For HPLC-UV analysis of extracted PAHs, the calibration curves were linear in the range of 0.05-80.0 µg L(-1); the coefficients of determinations (r(2)) were between 0.9934 and 0.9995. The relative standard deviations (RSDs) for eight replicates at two concentration levels (0.5 and 4.0 µg L(-1)) of PAHs were lower than 7.3%, under optimized conditions. The limits of detection (LODs, S/N = 3) of the proposed method for the studied PAHs were 0.007-0.048 µg L(-1). The recoveries of spiked PAHs (0.5 and 4 µg L(-1)) in the wastewater and sea water samples ranged from 78% to 108%. The simplicity of experimental procedure, high extraction efficiency, short sample analysis, and using of low cost sorbent demonstrate the potential of this approach for routine trace PAH analysis in water and wastewater samples.

Sulfur-nanoparticle-based method for separation and preconcentration of some heavy metals in marine samples prior to flame atomic absorption spectrometry determination.

The application of sulfur-nanoparticle-loaded alumina as an efficient adsorbent for the solid-phase extraction (SPE) and determination of trace amounts of Cd, Cu, Zn, and Pb ions was investigated in marine samples using flame atomic absorption spectrometry (FAAS). The nanometer-sized sulfur particles were synthesized in situ, physically loaded onto alumina microparticles, and the parameters influencing the preconcentration of the analytes, such as the pH, solution flow rate and volume, eluent solution, and interfering ions, were examined. The results showed that the optimal conditions for quantitative recovery of the metal ions by adsorption and elution on the sulfur nanoparticles (SNPs) was achieved by employing a flow rate of 15 mL min(-1), a pH of 8.5 for the sample solutions, and an eluent composed of 3.0 mol L(-1) HNO(3) in methanol. The detection limits of this method for Cd, Zn, Cu, and Pb ions were 0.30, 0.21, 0.24, and 0.63 µg L(-1) (n=10), respectively. Application of the proposed method to the analysis of fish certified reference material (DORM-3) produced results that were in good agreement with the certified values. The proposed method was also successfully applied to the determination of analytes in marine samples, including seawater, fish, and oysters.