Optimization of a methodology for determination of iron concentration in aqueous samples using a newly synthesized chelating agent in dispersive liquid-liquid microextraction

Probabilistic health risk assessment of heavy metals (Cd, Pb, and As) in Cocoa powder (Theobroma cacao) in Tehran, Iran market

The concentrations of toxic elements were analyzed by using Flame Atomic Absorption Spectrophotometer (FAAS). Moreover, the human health risk was estimated by Total Target Hazard Quotient (TTHQ) and Cancer Risk (CR) in Monte Carlo Simulation (MCS) technique. The mean concentrations (mg/kg) of Cd (0.08 ± 0.08), Pb (0.23 ± 0.46), and As (0.06 ± 0.04), were in a good compliance with ISO (Iranian standard organization). TTHQ for adults and children was equal to 0.009 and 0.042, respectively and also mean CR in adults and children consumers was equal to 9.73E-7 and 9.08E-7, respectively. Consequently, the concentration of toxic elements (Cd, Pb, and As) in cocoa powder did not pose any safety concerns. Moreover, probabilistic health risk assessment revealed that both adults and children were not at considerable non-carcinogenic (THQ and/or TTHQ ≤ 1) and carcinogenic risk (CR ≤ 1E-6). Even though, seeking for mitigating solutions and applying them to suppress the dangers of food containing toxic elements is a critical subject.

Microextraction procedures for preconcentration of Fe (III) in water and food samples prior to colorimetric detection: a comparative study

Two extraction procedures, namely dispersive liquid-liquid microextraction (DLLME) and dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFOD), have been compared for the spectrophotometric determination of Fe (III). In both procedures, Fe (III) was extracted after complexation with gallic acid in the presence of cetyltrimethylammonium bromide (CTAB). Tetrachloroethylene and 1-undecanol were used as extraction solvents in DLLME and DLLME-SFOD, respectively, while acetone was used as dispersing solvents. The effects of various experimental parameters (solution pH, the concentration of ligand and CTAB, as well as nature and amount of extraction and disperser solvents) on the extraction efficiency were investigated. Under optimum conditions, the calibration graphs were linear in the range of 50.0–650.0 and 8.0–800.0 μg L−1 and the detection limits were 15.0 and 5.0 μg L−1 for DLLME and DLLME-SFOD, respectively. The presence of NaCl, up to 1.0% (w/v) did not impact the extraction procedures. The analyte was good tolerated in the presence of most concomitant ions. The procedures were applied for the determination of Fe (III) in standard reference materials and real samples with good recoveries (95.5–99.0%) for DLLME-SFOD while poor recoveries (68.0–82.5%) were obtained when DLLME was applied. The analytical figures of the procedures were comparable with those listed in the literature and it could be concluded that DLLME-SFOD may be considered one of the best tools used for preconcentration of Fe (III), owing to its simplicity, time-saving and the possibility of using in conventional analytical laboratories.

Graphical abstract

Concentration of potentially harmful elements (PHEs) in eggplant vegetable (Solanum melongena) irrigated with wastewater: a systematic review and meta-analysis and probabilistic health risk assessment

The main objectives of this study were PHEs concentration meta-analysis (Fe, Zn, Cr, Ni, Cu, Pb, and Cd) in eggplant irrigated by wastewater and the following estimation of non-carcinogenic (n-CR) risk for the consumers based on countries. According to the results, the rank order of PHEs concentration in eggplant was Fe (88.3 mg/kg -dry weight) > Zn (10.1 mg/kg -dry weight) > Pb (3.0 mg/kg -dry weight) > Ni (2.7 mg/kg -dry weight) > Cu (1.1 mg/kg -dry weight) > Cd (0.9 mg/kg -dry weight) > Cr (0.05 mg/kg -dry weight). Moreover, n-CR risk showed that all investigated countries (China, India, Pakistan, Turkey, and Jordan) except for United Arab Emirates (UAE) had a considerable n-CR in both age groups (adults and children).

Potentially Toxic Elements (PTEs) in the Fillet of Narrow-Barred Spanish Mackerel (Scomberomorus commerson): a Global Systematic Review, Meta-analysis and Risk Assessment

The contamination of seafood like narrow-barred Spanish mackerel (Scomberomorus commerson) fillets by potentially toxic elements (PTEs) has converted to worldwide health concerns. In this regard, the related citations regarding the concentration of PTEs in fillets of narrow-barred Spanish mackerel were collected through some of the international databases such as Scopus, Cochrane, PubMed, and Scientific Information Database (SID) up to 10 March 2020. The concentration of PTEs in fillets of narrow-barred Spanish mackerel fish was meta-analyzed and the health risk (non-carcinogenic risk) was estimated by the total target hazard quotient (TTHQ). The meta-analysis of data indicated that the rank order of PTEs in fillet of narrow-barred Spanish mackerel was Fe (10,853.29 μg/kg-ww) > Zn (4007.00 μg/kg-ww) > Cu (1005.66 μg/kg-ww) > total Cr (544.14 μg/kg-ww) > Mn (515.93 μg/kg-ww) > Ni (409.90 μg/kg-ww) > Pb (180.99 μg/kg-ww) > As (93.11 μg/kg-ww) > methyl Hg (66.60 μg/kg-ww) > Cd (66.03 μg/kg-ww). The rank order of health risk assessment based on the country by the aid of TTHQ for adult consumers was Malaysia (0.22251) > Philippines (0.21912) > Egypt (0.08684) > Taiwan (0.07430) > Bahrain (0.04893) > Iran (0.03528) > China (0.00620) > Pakistan (0.00316) > Yemen (0.00157) > India (0.00073). In addition, the rank order of health risk assessment based on the country by the aid of TTHQ for child consumers was Malaysia (1.03838) > Philippines (1.02257) > Egypt (0.40523) > Taiwan (0.34674) > Bahrain (0.22832) > Iran (0.16466) > China (0.02892) > Pakistan (0.01474) > Yemen (0.00731) > India (0.00340). Therefore, the children in Malaysia and the Philippines were at considerable non-carcinogenic risk. Hence, approaching the recommended control plans in order to decrease the non-carcinogenic risk associated with the ingestion of PTEs via the consumption of narrow-barred Spanish mackerel fish fillets is crucial.

Multivariate optimization of a dispersive liquid-liquid microextraction method for determination of copper and manganese in coconut water by FAAS

In this study, multivariate methodologies were applied in the optimization of a dispersive liquid-liquid microextraction (DLLME) method, aiming at the determination of Cu and Mn in coconut water samples by flame atomic absorption spectrometry. Some extractors (chloroform and CCl₄), dispersants (ethanol, methanol and acetonitrile) and complexing agents (5-Br-PADAP and Dithzone) were previously tested in the extraction. A mixture design was used to optimize the component proportions formed by chloroform (10%), acetonitrile (76%), and 0.020% 5-Br-PADAP solution (14%). Doehlert design optimized the variables pH, NaCl, and buffer amounts for the extraction of both metals. The following analytical characteristics, respectively for Cu and Mn, were accessed: limit of quantification (4.83 and 3.32 µg L^-1), enrichment factors (11 and 8 fold), and precision (6.6 and 6.0% RSD, n = 10). Addition/recovery tests of the analytes allowed to find values in the range of 96.5-120% for Cu and 99-107% for Mn.

The concentration and probabilistic risk assessment of potentially toxic elements in fillets of silver pomfret (Pampus argenteus): A global systematic review and meta-analysis

The contamination of fish type products such as silver pomfret fish fillets by potentially toxic elements (PTEs) has raised global health concerns. Related studies regarding the concentration of PTEs in fillets of silver pomfret fish were retrieved among some international databases such as Scopus, PubMed and Embase between 1 January 1983 and 10 March 2020. The pooled (mean) concentration of PTEs in fillets of silver pomfret fish was meta-analyzed with the aid of a random-effect model (REM). Also, the non-carcinogenic risk was estimated via calculating the 95th percentile of the total target hazard quotient (TTHQ). The meta-analysis of 21 articles (containing 25 studies or data reports) indicated that the ranking of PTEs in fillets of silver pomfret fish was Fe (11,414.81 µg/kg wet weight, ww) > Zn (6055.72 µg/kg ww) > Cr (1825.79 µg/kg ww) > Pb (1486.44 µg/kg ww) > Se (1053.47 µg/kg ww) > Cd (992.50 µg/kg ww) > Ni (745.23 µg/kg ww) > Cu (669.71 µg/kg ww) > total As (408.24 µg/kg ww) > Co (87.03 µg/kg ww) > methyl Hg (46.58 µg/kg ww). The rank order of health risk assessment by country based on the TTHQ for adult consumers was Malaysia (2.500) > Bangladesh (0.886) > Iran (0.144) > China (0.045) > Pakistan (0.020) > India (0.015), while the corresponding values for child consumers was Malaysia (11.790) > Bangladesh (4.146) > Iran (0.675) > China (0.206) > Pakistan (0.096) > India (0.077). The adult consumers in Malaysia and children in Malaysia and Bangladesh were at considerable non-carcinogenic risk. Therefore, following the recommended control plans in order to reduce the health risk associated with the ingestion of PTEs via consumption of silver pomfret fish fillets is crucial.

Sensitive SQUID Bio-Magnetometry for Determination and Differentiation of Biogenic Iron and Iron Oxide Nanoparticles in the Biological Samples

This study aimed to develop the method for determination of the ultra-small superparamagnetic iron oxide nanoparticle (USPION)-originated iron (UOI) in the tissues of rats on the basis of the magnetic characteristics (MC) in the liver, left heart ventricle (LHV), kidneys, aorta and blood of Wistar-Kyoto (WKY). Rats were treated intravenously by USPIONs dispersed in saline (transmission electron microscope (TEM) mean size ~30 nm, hydrodynamic size ~51 nm, nominal iron content 1 mg Fe/mL) at the low iron dose of 1 mg/kg. MC in the form of the mass magnetisation (M) versus the magnetic field (H) curves and temperature dependences of M (determined using the SQUID magnetometer), histochemical determination of iron (by Perl's method) and USPION-induced superoxide production (by lucigenin-enhanced chemiluminescence) were investigated 100 min post-infusion. USPIONs significantly elevated superoxide production in the liver, LHV, kidney and aorta vs. the control group. Histochemical staining confirmed the presence of iron in all solid biological samples, however, this method was not suitable to unequivocally confirm the presence of UOI. We improved the SQUID magnetometric method and sample preparation to allow the determination of UOI by measurements of the MC of the tissues at 300 K in solid and liquid samples. The presence of the UOI was confirmed in all the tissues investigated in USPIONs-treated rats. The greatest levels were found in blood and lower amounts in the aorta, liver, LHV and kidneys. In conclusion, we have improved SQUID-magnetometric method to make it suitable for detection of low amounts of UOI in blood and tissues of rats.

Trace Determination of Iron in Real Waters and Fruit Juice Samples Using Rapid Method: Optimized Dispersive Liquid-Liquid Microextraction with Synthesized Nontoxic Chelating Agent

The purpose of this research was to optimize a new method for preconcentration and determination of trace iron concentrations in aqueous solutions. For this purpose, a newly synthesized ligand, 3-(3-hydroxy-2-methyl-4-oxopyridin-1(4H)-yl) benzoic acid (3-OH-3-MOPBA), was used in the dispersive liquid-liquid microextraction (DLLME) method coupled with UV-vis spectroscopy. The experiments considering input variables of extractant volume, disperser volume, salt concentration, and pH were designed with the aid of central composite design (CCD). The results were analyzed using response surface methodology (RSM). The limit of detection (LOD) was found to be 4.0 μg L^-1 under the optimized conditions. A calibration curve with a good linearity (R² = 0.9986) was obtained over the concentration range of 15-800 μg L^-1. The relative standard deviations (RSD) were found to be around 2.1% (n = 7). The main advantages of the developed method are simple application, environment friendly, short time, and low cost which makes this method to be applied routinely for measuring iron in various water samples.

Properties Analysis of Oil Shale Waste as Partial Aggregate Replacement in Open Grade Friction Course

Open graded friction course (OGFC) is a high permeable mixture used to reduce noise, improve friction. However, limitations with the use of OGFC are due to the relatively low strength and stiffness. Therefore, investigating environmental and economic benefits, as well as service life of OGFC technology is the future of the pavement. In this study, a new modified OGFC (SM-OGFC) was prepared by replacing the fine aggregate below 4.75 mm in OGFC with the oil shale waste (OSW), and the silane coupling agent modifier was used to assist modification. The preparation process of SM-OGFC was optimized by central composite design, to obtain an SM-OGFC with the best mechanical properties. The Marshall test, rutting test, −15 °C splitting test, −10 °C beam bending test, immersion Marshall test, spring-thawing stability test, Cantabro test and permeability test were conducted to evaluate the properties of SM-OGFC. The results prove that SM-OGFC has excellent overall performance in comparison with OGFC and styrene-butadiene-styrene (SBS) modified OGFC. Furthermore, Scanning Electron Microscopy (SEM) observation illustrates that the unique laminar columnar connected structure and cell-like structure antennae of OSW could be the main reasons why SM-OGFC obtained excellent performance. Furthermore, economic analysis indicated that the SM-OGFC mixture had higher cost effectiveness.