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Analytical and Bioanalytical Chemistry Research - Volume:1 Issue: 2, Summer - Autumn 2014

Analytical and Bioanalytical Chemistry Research
Volume:1 Issue: 2, Summer - Autumn 2014

  • تاریخ انتشار: 1393/12/11
  • تعداد عناوین: 7
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  • Akram Rahimi, Payman Hashemi, Gholam Reza Talei, Mohammad Borzuei, Ali Reza Ghiasvand Pages 83-91
    The volatile components of Citrus aurantium L. flowers were characterized by GC-MS with two different extraction techniques, hydrodistillation (HD) and ultrasonic-assisted headspace solid phase microextraction (UA-HS-SPME). In the SPME method, the volatile components of the samples, irradiated by ultrasonic radiation, were collected on a polydimethyl siloxane (PDMS) commercial fiber as well as some manually prepared nanoporous fibers from the samples headspace. To reach the better results, the extraction conditions were carefully optimized for the PDMS fiber. Under the optimized conditions (i.e. sonication time 15 min, extraction time 30 min and extraction temperature 55 ºC), 54 compounds were identified by the UA-HS-SPME-GC/MS method. The essential oil components of Citrus aurantium L. flower samples from two different regions of Iran and new and old samples from the same region were compared to one another. The major components identified for the samples with both the SPME and HD methods were linalool, linalyl acetate, limonene, β-myrcene, geranyl acetate, and neryl acetate, respectively. However, a substantial variation in the percentages of the components was identified for different samples and different extraction methods. The antimicrobial activities of the oil were also examined against six standard bacteria. There was some activity against Enterococcus fecalis, Escherichia coli, and Bacillus cereus, indicating important biological activities of the oil.
    Keywords: Ultrasonic, assisted headspace SPME (UA-HS-SPME), Polydimethyl siloxane, Citrus aurantium L. flowers, Antimicrobial activity
  • Jahan Bakhsh Raoof, Abolfazl Kiani, Reza Ojani, Roudabeh Valiollahi Pages 92-98
    The electrochemistry of banana tissues on a carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) is presented. Cyclic voltammetry is applied to investigate the direct electrochemistry of banana tissues i.e. a source of polyphenol oxidase (PPO). A redox couple with an anodic and counterpart cathodic peak is obtained. The influence of various parameters such as pH, scan rate of potential and heating on the electrochemical properties of polyphenol oxidase in banana tissues were examined. For apple tissues, a same signal is observed on a carbon paste electrode (CPE) modified with multi-walled carbon nanotubes. It was found that presence of carbon nanotubes (CNTs) is essential to observe the electrochemical activity of polyphenol oxidase in banana and apple tissues. In this paper, the electrochemistry of fruits was described. We have shown that multi-walled carbon nanotubes can enhance the direct electron transfer between the electroactive center of polyphenol oxidase in banana tissues and the underlying electrode.
    Keywords: Multi-walled Carbon nanotubes, Direct electrochemistry, Cyclic voltammetry, banana, Polyphenol oxidase, Modified carbon paste electrode
  • Mohammad Bagher Gholivand, Yadollah Yamini, Manijeh Dayeni Pages 99-107
    A comparative study of ultrasound-assisted extraction (UAE) and hydro-distillation was performed for fast extraction of estragole from tarragon (Artemisia dracunculus L.) dried leaves. Several influential parameters of the UAE procedure in the extraction of estragole (type of solvent, extraction cycles, solvent to material ratio, irradiation time and particle size) were investigated and optimized. It was found that UAE offers a more rapid extraction of estragole than hydrodistillation. The optimum parameters were solvent to material ratio of 8:1 v/m, 96% (w/w) ethanol in water as extraction solvent, particle size of 1.18 mm, irradiation time of 5 min, output power of 63 W, 9 pulses, and ultrasonic frequency of 20 kHz. The recovery of estragole by UAE under optimal conditions was 44.4% based on dry extract. The benefit of ultrasound was to decrease the extraction time (5 min) relative to the classical hydrodistillation method (3 h). The experimental results also indicated that ultrasound-assisted extraction is a simple, rapid and effective method for extraction of the volatile oil components of tarragon.
    Keywords: Artemisia dracunculus L, Tarragon, Estragole, Ultrasound, assisted extraction, Essential oil, Hydrodistillation
  • Fariborz Momenbeik, Faezeh Tajmir Riahi Pages 108-116
    In this project, eggshell membrane was used as a solid phase extraction sorbent for extraction of morphine followed by HPLC analysis. At first, raw eggshell membrane was used and then, because of low adsorption of morphine on untreated eggshell membrane (
    Keywords: High performance liquid chromatography, Solid phase extraction, Eggshell membrane, morphine
  • Javad Tashkhourian, Morteza Akhond, S. Hooshmand, T. Khosousi, B. Hemmateenejad Pages 117-127
    Glucose, as the major energy source in cellular metabolism, plays an important role in the natural growth of cells. Herein, a simple, rapid and low-cost method for the glucose determination by utilizing glucose oxidase and CdTe/thioglycolic acid (TGA) quantum dots (QDs) on a thin layer chromatography (TLC) plate has been described. The detection was based on the combination of the glucose enzymatic reaction and the quenching effect of H2O2 on the CdTe/TGA quantum dots photoluminescence. This QDs-based assay exhibits several advantages. Enzyme immobilization and QDs modification process are not required and the high stability of the QDs towards photobleaching is beneficial to this sensing system. The proposed method is linear in concentration range of 1.00 × 10-1-3.00 × 10-5 M of glucose and has a detection limit of 1.25 × 10-8 M. The results of real sample analysis show that the glucose oxidase CdTe/TGA QDs system would be a promising glucose-biosensing system.
    Keywords: Image analysis, CdTe, TGA Quantum dots, glucose, Glucose oxidase
  • Ali Kamal Attia, Mona Abd, Elmoety, Amr M. Badawy, Abd Elazis Abd Elaleem, Samar G. Abd Elhamid Pages 128-138
    A simple, precise, inexpensive and sensitive voltammetric method has been developed for the determination of gemifloxacin mesylate (GEM) in the presence of tween 80 in the bulk, farmaceutical dosage forms and human urine at gold nanoparticles modified carbon paste electrode (GNCPE). The electrochemical behavior of GEM has been investigated by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The electrochemical oxidation of GEM was an irreversible process which exhibited adsorption-diffusion controlled process behavior in Britton-Robinson (BR) buffer over the entire pH range of values from 2 to 9. The adsorptive stripping response was evaluated as a function of some variables such as pH, type of surfactant, scan rate and accumulation time. The anodic peak current varied linearly over the range from 8.0 × 10-7 to 2.8 × 10-5 M. The limits of detection and quantification were 7.32 × 10-8 M and 2.44 × 10-7 M, respectively. The relative standard deviations and the percentage recoveries were found in the following ranges: 0.58-1.35% and 99.37-101.76%, respectively.
    Keywords: Gemifloxacin, Gold Nanoparticles, Voltammetry, Tween 80, Urine
  • M.Reza Hormozi Nezhad, Sena Ghayyem Pages 139-146
    We report herein the development of a highly sensitive colorimetric method for the detection of 4-hydroxy-2-mercapto-6-methylpyrimidine (MTU) which acts as an anti-thyroid drug utilizing citrate capped gold nanoparticles (Au-NPs). This thiol-containing molecule exhibits intriguing affinity with Au-NPs. The reactivity involves the displacement of the citrate shell by the thiolate shell followed by intermolecular electrostatic interactions or hydrogen-bonding between the thiolate shells. The interparticle interactions depend on ionic strength, pH and Au-NPs concentration of the solution. The interparticle interactions lead to a small change in the plasmon band around 521 nm and the formation of a new red shifted band. The calibration curve is derived from the ratio of the absorption intensity changes at 650 nm to the changes at 520 nm. It was linear in the concentration range of 5.0 × 10-7-2.75 × 10-6 M. The detection limit (3σ) for MTU was found to be 1.9 × 10-7 M.
    Keywords: Gold Nanoparticle, 4-Hydroxy-2-mercapto-6-methylpyrimidine, Colorimetric detection