Kobra Sadat Hasheminasab

Wheat is a major staple crop worldwide, making the assessment of heavy metal contamination a critical concern for food safety and public health. This study presents a nationwide evaluation of cadmium (Cd) and lead (Pb) concentrations in wheat grains and corresponding agricultural soils across five major agroecological zones in Iran. A total of 2016 wheat grain samples and 690 soil samples were collected from representative wheat-growing regions during 2018–2021 and analyzed using validated analytical methods. The results revealed that the mean concentrations of Cd (0.011 mg/kg) and Pb (0.032 mg/kg) in wheat grains were below the maximum permissible limits set by national and international standards. However, spatial analysis identified localized contamination hotspots, particularly in northern and western provinces, where metal concentrations approached regulatory thresholds. Soil pollution indices generally indicated low contamination levels and low ecological risk at the national scale, with slight enrichment observed in limited areas. Soil–grain relationships were weak but statistically significant, suggesting that Cd and Pb uptake is influenced by soil pH, organic matter content, wheat cultivar, and agricultural management practices. The predominantly alkaline nature of soils in the studied regions appears to reduce Cd and Pb bioavailability and imit their transfer into wheat grains. Health risk assessment based on estimated dietary intake revealed Hazard Quotient values (HQ < 1) for both metals, indicating no significant non-carcinogenic risk associated with wheat consumption under average dietary scenarios. Overall, although current contamination levels do not pose a significant public health risk, the findings highlight the need for continued regional monitoring to sustain safe wheat production and prevent future accumulation.

Vegetables are the major source of dietary nitrate, with a wide range of nitrate content. The presence of nitrate in vegetables is often associated with harmful effects on human health, i.e. with toxic effects of methemoglobinemia and the possibility of causing an endogenous formation of carcinogenic N-nitroso compounds. Therefore, accurate measurement of nitrate in these products is of great importance. Various analytical techniques have been developed to determine nitrate in biological samples and vegetables. The purpose of this study is to compare the three methods BS EN 12014-2 (HPLC UV/Vis), ISO 6635, and Cd-column for nitrate measurement and to introduce an accurate, safe, and useful method for nitrate measurement in 11 important vegetables with a wide range of nitrate content. The results of this study showed strong agreement between the three methods. A strong and significant regression was observed between the HPLC run using ISO 6635 and the HPLC method using the Cd-column, with the slope of the regression curve close to 1 for most of the vegetable samples. Between HPLC and ISO 6635 methods, the fitted regression curve had slopes as high as 1.0946 and as low as 0.9195, respectively. While, the highest and lowest slopes of the fitted regression curve between HPLC and the Cd-column methods were 1.088 and 0.9217, respectively. The highest slope between the two methods ISO 6635 and Cd-column was equal to 1.0832 and the lowest was equal to 0.8421. The correlation coefficient of the regression equation was significant at a level of 99% (p ˂ 0.01) across all samples and correlations of linear regression. The results of this study showed that all three methods have high accuracy for nitrate measurement in vegetables. However, the type of sample and the accessibility of the facility plays a big role in the selection of an analytical method. The HPLC method is slower than the Spectrophotometry methods (ISO 6635 and Cd-column), despite having a higher initial investment cost. However, it has a lower risk of environmental pollution and health risk for the staff. Spectrophotometry methods have high speed, and the initial cost of equipment is lower, but they have more environmental risk and are labor-intensive than the HPLC method. Finally, despite the fact that the compared methods were very accurate at measuring nitrate in vegetables, the HPLC method is suggested because it is reliable, secure, and practical in vegetables due to the figure of merits mentioned.

Herein, an efficient carrier assisted electromembrane extraction coupled with capillary electrophoresis has been proposed for the quantitation of basic drugs (pseudoephedrine and tramadol) in urine samples. Nonionic lipophilic surfactants in the supported liquid membrane act as carriers and promote the migration of ionic analytes toward the acceptor phase. The volumes of the sample and acceptor solutions were 4000 and 20 μL, respectively. All variables affecting the extraction efficiency were investigated for the proposed method. Optimal extractions were accomplished with 2-nitrophenyl octyl ether, containing 0.25 mM Span 80 as the supported liquid membrane, with 200 V as the driving force and with pH 5.0 in donor and pH 1 in acceptor solutions. Extractions were obtained after 30 min of operation with the whole assembly agitated at 1000 rpm. Under the optimum experimental conditions, the linear range was 10–2000 and 5–2000 ng mL⁻¹ for pseudoephedrine and tramadol, respectively (R² ≥ 0.99). The limits of detection were calculated to be 3.03 and 1.51 ng mL⁻¹ for pseudoephedrine and tramadol, respectively. The relative standard deviation was lower than 4.1%. The enrichment factors were in the range of 178 to 188. The method was successfully applied for the analysis of these drugs in urine samples.

A simple, fast, sensitive, and low‐cost method was developed for the quantification of nitroaromatic compounds in water samples based on CO₂‐assisted liquid‐phase microextraction using a switchable‐hydrophilicity solvent followed by gas chromatography detection. Dipropylamine was used as extraction solvent with switchable hydrophilicity that can be miscible or immiscible upon the addition or removal of CO₂ as a reagent. Experimental parameters affecting the extraction efficiency such as the volume of acceptor phase, the volume of donor phase, pH of donor phase, ionic strength, and extraction time were investigated. Under the optimal conditions, detection limits and preconcentration factors were obtained in the ranges of 0.9–1.8 μg/L and 132–138, respectively. Also, the extraction recoveries of water samples were above 88%. Finally, the developed method was successfully applied to the determination of nitroaromatic compounds in real water samples.

In this paper, for the first time, surfactant‐assisted electromembrane extraction coupled with capillary electrophoresis with UV detector was introduced for the extraction of acidic drugs from biological fluids. In this technique, in the presence of the nonionic surfactant in the donor phase, tendency of analyte ions into the supported liquid membrane (SLM) was increased. Naproxen and diclofenac were selected as model acidic drugs. In order to obtain the best extraction efficiency, several factors influencing the extraction efficiency were investigated. Optimal extractions were accomplished with 1‐octanol as the SLM, 15 Volt dc potential as the driving force, pH 12 in acceptor solution, and 0.2 mmol/L Triton X‐100 with pH 7.4 in donor solution. Equilibrium extraction conditions were obtained after 15 min of operation where the whole assembly agitated at 1000 rpm. Under the optimized conditions, preconcentration factors in the range of 176–184 and recoveries in the range of 88–92% were obtained. The applied method offers acceptable linearity with correlation coefficients higher than 0.9992. Limits of detection of 1.51 ng/mL and 2.42 ng/mL were obtained for naproxen and diclofenac, respectively. Finally, the developed method was successfully applied for the determination of naproxen and diclofenac in different matrices including plasma and urine samples.