Showing 2 results for Marjani
Nasrin Alvand, Mohammad Alimoradi, Majid Baghdadi, Azam Marjani, Tahereh Momeni-Isfahani,
Volume 18, Issue 2 (7-2022)
Abstract
Background: In the present study, an environmentally friendly microextraction of nickel based on solid-phase using iron metal coupled to flame atomic absorption spectrophotometry was investigated. Due to elimination of organic solvents, this method can be used as a green technique to extract and reduce the detection limit of nickel in water samples.
Methods: By adding 0.06 g sodium borohydride (NaBH4) to 100 ml of the solution containing Fe (II) ions with concentration of 12 mg/l and nickel, these ions were converted to zero-valent particles. The nickel revived particles were trapped in the iron microparticles and deposited with them. After that, the produced solid phase produced was dissolved in 200 ml of hydrochloric acid (HCl) 6N and the nickel concentration was measured using atomic absorption method. To optimize the process, effect of pH (1 to 8), the amount of potassium hydrogen phthalate (KHP) (0.02-0.30), Fe (II) concentration (2.20-5.00 mg/l), NaBH4 (0.20-0.01 g), time (0.5-15.00 minutes), and temperature (20-80 °C) were investigated. In addition, the effect of interfering ions was evaluated. Finally, the figures of merit were calculated, and the function of the method was investigated in the real water samples.
Findings: According to the performed optimization, pH = 4.5, NaBH4 = 0.06 g, Fe (II) = 2.5 mg/l, KHP = 0.08 g, time= 4 minutes, temperature = 50 °C, and sample size = 100 ml were the optimum conditions. Besides, the concentration factor of 410, the detection limit of 0.3 ng/ml, and relative standard deviation (RSD) of 2.7% were obtained.
Conclusion: Due to the low detection limit and the elimination of organic solvents in nickel microextraction, this method can be a suitable method for determining trace amount of nickel with high efficiency. The low detection limit is due to the high concentration factor, which is significantly higher than the other microextraction methods.
Farideh Roustaei, Majid Baghdadi, Azam Marjani, Mohammad Alimoradi,
Volume 19, Issue 3 (10-2023)
Abstract
Background: Bisphenol A is known as one of the emerging micropollutants with harmful effects on human health. This pollutant enters the environment through the discharge of municipal wastewater treatment plants. In this research, the salting out dispersive liquid-liquid microextraction method was investigated for pre-concentration of bisphenol A in drinking water and urban sewage effluent samples. Due to the high enrichment factor, this method enables the measurement of small amounts of bisphenol A in the examined samples.
Methods: In this method, bisphenol A forms a colored hydrophobic derivative of antipyrine with 4-aminoantipyrine in the presence of potassium hexacyanoferrate. In order to extract the resulting derivative, 250 µl of 2-phenoxyethanol was dissolved in 10 ml of the sample. Then, by adding 0.7 g of sodium chloride to the sample, fine droplets of extracting solvent were formed in the sample and the solution became cloudy. After centrifugation, the extraction phase containing bisphenol A derivative settled at the bottom of the test tube, and then, 20 µl of methanol was added in order to reduce its viscosity. The measurement was performed by a high-performance liquid chromatography at a wavelength of 480 nm. To optimize the process, the effect of the amount of 4-aminoantipyrine, potassium hexacyanoferrate, and buffer was investigated. Then, the figures of merit of the method were obtained and the performance of the method was evaluated on drinking water and urban sewage effluent samples.
Findings: Under optimal conditions (2-phenoxyethanol: 250 µl, 4-aminoantipyrine 1%: 100 µl, potassium hexacyanoferrate 10%: 80 µl, buffer pH 10: 10 µl, and sodium chloride: 0.7 g per 10 ml of sample), the enrichment factor of 106, the detection limit of 0.1 ng ml-1, the limit of quantification of 0.3 ng ml-1, and the relative standard deviation (RSD) of 3.2% were obtained. Meanwhile, the correlation coefficient (CC) of the calibration curve was equal to 0.9985. Moreover, the results of the analysis of water and urban sewage effluent samples showed that the developed method had suitable performance for the measurement of bisphenol A in real matrix samples.
Conclusion: Considering the low detection limit, high enrichment factor, and proper performance in real samples, this method can be introduced as a sensitive and efficient method for the measurement of very low amounts of bisphenol A in water and wastewater samples.
