کاربردهای شیمی تجزیه
Negar Gholhovallahi; Ali Sheibani
Abstract
Ion mobility spectrometry is an analytical technique with main advantages such as high sensitivity, fast response and simplicity. The purpose of this work was to determine of mesalazine in different pharmaceutical samples using ion mobility spectrometry with a positive corona ionization source. After ...
Read More
Ion mobility spectrometry is an analytical technique with main advantages such as high sensitivity, fast response and simplicity. The purpose of this work was to determine of mesalazine in different pharmaceutical samples using ion mobility spectrometry with a positive corona ionization source. After obtaining the best instrumental parameters (injection temperature: 230 ºC, cell temperature: 180 ºC, drift voltage: 6800 V, corona voltage: 2400 V, flow rate of drift gas: 600 mL/min and flow rate of carrier gas: 300 mL/min) the linear dynamic range was 1.0–70.0 ng with a determination coefficient, R2=0.9881. The relative standard deviation values were lower than 6.0% (n=5) for the examined range (10.0–60.0 ng) of the drug. The limit of detection and limit of quantitation were 0.3 ng and 1.0 ng, respectively. The capability of the developed method was evaluated for the determination of mesalazine in tablet, capsule, and suppository as pharmaceutical samples. Satisfactory recovery results were obtained in the range of 98.0–103.8%.
کاربردهای شیمی تجزیه
Mohammad Bagi; Masoumeh Tabatabaee; Ali Sheibani
Abstract
Fluoride impurities in industrial zinc sulfate electrolytes adversely affect the zinc electrowinning process by promoting zinc deposition on the aluminum cathode, thereby reducing process efficiency and product quality. In the present study, zirconium oxide (ZrO2) has been used as an adsorbent to remove ...
Read More
Fluoride impurities in industrial zinc sulfate electrolytes adversely affect the zinc electrowinning process by promoting zinc deposition on the aluminum cathode, thereby reducing process efficiency and product quality. In the present study, zirconium oxide (ZrO2) has been used as an adsorbent to remove fluoride of zinc sulfate solution during the industrial electrolysis process of zinc production. The effects of five operational parameters, including ZrO2 dosage, temperature, contact time, stirring speed and pH were systematically evaluated to optimize the fluoride removal process. The initial concentrations of zinc sulfate and fluoride in the electrolyte were 210 g/L and 453 mg/L (ppm), respectively. Under the optimum operating conditions (ZrO2 dosage of 2.0 g/L, temperature of 90 °C, contact time of 20 min, stirring speed of 200 rpm, and also pH 7), more than 90% of the fluoride was removed from the zinc sulfate electrolyte. Moreover, under industrial operating conditions demonstrated that the fluoride concentration could be reduced to below 55 mg/L (adsorption capacity=200 mg/g), significantly alleviating operational problems associated with zinc electrowinning. These findings demonstrate that ZrO2 nanopowder is an efficient and practical adsorbent for fluoride removal from industrial zinc sulfate electrolytes and has considerable potential for industrial application.
Farideh Shamsi; Ali Sheibani; M. Reza Shishehbore
Abstract
In this study, a dispersive magnetic solid phase extraction (DMSPE) was described by combining graphene oxide (GO) with Fe3O4 and CuO (Fe3O4@CuO&GO) for extraction and preconcentration of aspirin (ASP) in biological samples. The morphology and structure of the prepared nanocomposite was characterized ...
Read More
In this study, a dispersive magnetic solid phase extraction (DMSPE) was described by combining graphene oxide (GO) with Fe3O4 and CuO (Fe3O4@CuO&GO) for extraction and preconcentration of aspirin (ASP) in biological samples. The morphology and structure of the prepared nanocomposite was characterized and analyzed by XRD, SEM and FTIR techniques. Ion mobility spectrometry (IMS) method equipped to a corona discharge ionization source was exploited to determine ASA. The extraction parameters (desorption solvent, pH, adsorbent amount, extraction time and temperature) and also the operational parameters of IMS were investigated and optimized. Under the optimum conditions, the DMSPE–IMS method provided a linear range 6.0–40.0 ng for ASA with coefficient of determination R2 = 0.99. The LOD and LOQ values were 0.9 and 3.0 ng for ASA, respectively. The repeatability of developed method was evaluated as relative standard deviation (RSD% = 2.7). The proposed method was also used to determine ASA in human plasma and serum as biological samples, which recovery results were within 89.0–100.0%.
Fatemeh Nourpishe; Ali Asghar Amiri; Ali Sheibani; Masoud Reza Shishehbore
Abstract
In this study, a simple and sensitive method was developed for pre-concentration of spirotetramat (SPT) using the ionic liquid-based dispersive liquid-liquid microextraction. After extracting of SPT into 1-butyl-3-methylimidazolium hexafluorophosphate (ionic liquid), the insecticide was injected into ...
Read More
In this study, a simple and sensitive method was developed for pre-concentration of spirotetramat (SPT) using the ionic liquid-based dispersive liquid-liquid microextraction. After extracting of SPT into 1-butyl-3-methylimidazolium hexafluorophosphate (ionic liquid), the insecticide was injected into HPLC system for determining. Under the optimum conditions, the developed method provided a linearity in the range of 0.05–2.0 µg mL-1 with R2= 0.9987, and also enrichment factor was 250. The detection limit and relative standard deviation of the developed method were 0.01 µg mL-1 and 2.7%, respectively. The proposed method was successfully applied to the pre-concentration and determination of SPT in spiked water samples with mean recoveries 94.0-96.0%.
S. Javad Aghili; Ali Sheibani; M. Reza Shishehbore
Abstract
In this paper, a simple, sensitive and economical method is described for the extraction and determination of sesame oil oxidation by dynamic headspace extraction combined to ion mobility spectrometry (IMS). Hexanal as a reaction product of oxidation, is used to follow the progress of oil oxidation. ...
Read More
In this paper, a simple, sensitive and economical method is described for the extraction and determination of sesame oil oxidation by dynamic headspace extraction combined to ion mobility spectrometry (IMS). Hexanal as a reaction product of oxidation, is used to follow the progress of oil oxidation. The optimization of different variables for the extraction step including: extraction temperature, extraction time and flow rate of carrier gas and also for the determination step by IMS including: drift and corona voltages, flow rate of carrier and drift gases, cell and injection temperatures, and pulse width were performed. Under optimum conditions, the calibration curve was linear in the range of 0.10 to 0.50 ng g-1 and also the relative standard deviation was 3.0%. The detection and quantification limits were 0.03 and 0.12 ng g-1, respectively. The recovery results for spiked samples (90.0-104.0%) demonstrated the potential of the proposed method for determining of oxidation in sesame oil samples.
Hadieh Habibagahi; Ali Sheibani; M. Reza Shishehbore
Volume 3, Issue 1 , March 2016, , Pages 70-75
Abstract
In this study, a third derivative spectrophotometric method based on zero-crossing technique is developed for the simultaneous determination of atenolol and propranolol. Effective parameters including temperature and pH were investigated and optimized. Under optimum experimental conditions (temperature: ...
Read More
In this study, a third derivative spectrophotometric method based on zero-crossing technique is developed for the simultaneous determination of atenolol and propranolol. Effective parameters including temperature and pH were investigated and optimized. Under optimum experimental conditions (temperature: 10 oC and pH: 8-10), calibration curves were linear between concentration ranges of 0.8 to 12.9 μg mL-1 of atenolol and 0.3 to 6.4 μg mL-1 of propranolol. The limit of detection was 0.2 μg mL-1 and relative standard deviation was lower than 3%. The proposed method was applied for the simultaneous determination of both drugs in the pharmaceutical formulations. Acceptable recoveries of the analytes, ranging from 97 to 107%, were obtained.
