فهرست مطالب

Journal of Chemical Health Risks
Volume:2 Issue: 4, Autumn 2012

  • تاریخ انتشار: 1391/09/18
  • تعداد عناوین: 8
|
  • C. S. Vergilio, Carvalho C. E. V., E. J. T. Melo Page 1
    The present study evaluated potential Hg bioaccumulation and its morphological effects in different organs of the tropical fish, Gymnotus carapo, after a single acute intra-peritoneal exposure (0.6 µg.g-1) and over progressively longer exposure times (24 h, 48 h, 72 h and 96 h). The Hg accumulation was differential and time dependent for most target organs (testis > liver > gills > muscle). Hg exposure leads the highest accumulation potential in testis since the initial examination point (24 h) until the last (96 h). The liver showed progressive Hg accumulation, presenting its highest levels only at the 96 h exposure point. Hg concentrations in the gills and muscle oscillated over the exposure times; however, the highest values of both organs also occurred in 96 h exposed fish. Histopathological alterations were observed in testis, liver and gills from 24 h of Hg exposure, and the extent of the alterations and their severity increased out to 96 h of exposure. These results shows a correlation between Hg accumulation and the induced morphological damages in different organs along the time in a tropical fish species G. carapo, being the histopathology a sensitive technique for the observation of the initial damage from Hg exposure.
  • A. S. Yousefi, A. Bostani Page 9
    Refining oil-contaminated soils has a great importance especially in oil producer countries such as Iran. Different methods have been provided to eliminate oil contaminations from soil. The aim of this study was to investigate the effect of Hydrogen peroxide concentration in refining oil-contaminated soils with Fenton chemical method. To do this, a calcareous soil complex sample was collected around the Tehran oil refinery and treated with 10 and 20 percent petroleum in three replications. After reaching to balance conditions, the sample was treated using0.01, 0.02,0.12,0.24,0.47 and 0.71 equivalent of Hydrogen peroxide. The results indicated that in all level of H2O2, the eliminating efficiency in 10 percent was more than 20 percent treatment. Also a significant difference between the levels of hydrogen peroxide used in the removal of oil pollution in both surface concentrations was obtained (P<0.01).
  • R. Alebooyeh, A. Mohammadinafchi, M. Jokr Page 13
    Nowadays tend to use biodegradable packaging; including edible coatings and films for free from synthetic chemicals and do not cause environmental pollution, the industry is growing day by day. The aim of this research was to preparation and characterization of biodegradable films supported with ZnOnanorods. In this study, sago starch based films were prepared and plasticized with sorbitol/ glycerol by casting method. ZnOnanorod with 0, 1, 3and 5%(w/w)was added to the films before casting the films. Films were dried at controlled conditions. Physicochemical properties such as water absorption capacity (WAC), permeability to water vapor (WVP) and water solubility of the films were measured. Also, the effects of addition of nano particles were measured on the antimicrobial properties of the films by agar diffusion method. Results showed that by increasing concentration of ZnOnanorod, solubility in water, WAC, and WVP of the films significantly (p <0.05) decreased. Furthermore, the addition of zinc oxide nanorods showed antimicrobial properties against E. Coli. In summary sago starch films supported with ZnOnanorodscan were used as active packaging for agricultural products as well as food industry.
  • M. Bashash, M. Bolandi, N. Zamindar Page 17
    In this study, the phenolic content of three sumac (R. coriaria L.) samples were evaluated including, brown sumac fruit, brown sumac powder and red sumac. Methanol, ethanol, mixture of methanol-ethanol and distilled water were used for extraction. Phenolic content was determined by Folin–Ciocaltaeu procedure. The efficiency of the extraction varied considerably. The phenolic content of brown sumac powder, brown sumac fruit and red sumac powder were 2.906-2.997, 2.438- 2.529, 2.172- 2.263 gallic acid equivalents/100 g (GAE/100 g), respectively. According to the results, ethanol shows the best results and sumac had highest phenolic content as compared to other extracts.
  • F. Bagheban, Shahri, A. Niazi, A. Akrami Page 21
    A new spectrophotometric method was developed for the simultaneous of ternary mixtures of nitrophenol isomers, without prior separation steps. This method is called the first derivative of the density ratio spectra. All factors affecting on the sensitivity were optimized and the linear dynamic range for determination of nitrophenol isomers was found. The method made use of a derivative of the double-divisor-ratio spectra of optical density. In this case, the linear determination ranges are 1.0-25.0 mg mL-1 for m-nitrophenol, 1.0-25.0 mg mL-1 for o-nitrophenol and 1.0-15.0 mg mL-1 for p-nitrophenol. The RMSEP for m-nitrophenol, o-nitrophenol and p-nitrophenol by proposed method was 0.4907, 0.4779 and 0.2068, respectively. The method developed in this paper was rapid, easy to apply, not expensive and it was suitable for analyzing to overlapping signals of compounds in their mixtures without any chemical pre-treatment and also, the proposed method was satisfactorily applied to the rapid simultaneous determination of m-nitrophenol, o-nitrophenol and p-nitrophenol in synthetic and water samples.
  • T. Ardalan, P. Ardalan, M. M. Heravi Page 37
    Saffron petal is the main by-product of saffron processing which is produced in large amounts, annually. The objectives of this study were to study the antioxidant activity and free radical-scavenging effects of saffron petal extracts. The ability of saffron petal to act as an antioxidant using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical method was investigated by applying the Uv–Vis spectrometry. The Uv–Vis spectra of reaction mixtures in acetonitrile revealed that saffron petal has a considerable effect on scavenging free radical. Kinetic studies were conducted by measuring the disappearance of DPPH in acetonitrile over the wavelength range of 515-522 nm under pseudo-first-order conditions at 37oC. Furthermore, the pseudo first order rate constants were determined
  • M. Momen Heravi, A. Kodabande, M. R. Bozorgmehr, T. Ardalan, P. Ardalan Page 37
    In this study, Chamomilla plant biomass used as a sorbent for biosorption of a textile dye, direct red 81, from an aqueous solution. The batch sorption was studied with respect to dye concentration, adsorbent dose and temperature. Also, kinetic and isotherm parameters were determined for biosorption of Direct red 81 by Chamomilla plant. The maximum biosorption capacity (qm) of Direct red 81 10 mg g-1 was obtained at 25oC. The kinetic and isotherm studies indicated that the biosorption process obeys a pseudo-second order and Langmuir isotherm models. In addition, various thermodynamic parameters, such as changes in Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) have been calculated. The biosorption process of Direct Red 81 dye onto activated carbon prepared from Chamomilla plant was found to be spontaneous and exothermic. The findings of this investigation suggest that this procces is a physical biosorption. The experimental studies indicated that Chamomilla plant had the potential to act as an alternative biosorbent to remove the Direct Red 81 dye from an aqueous solution.
  • A. Moghimi Page 45
    A novel and selective method for the fast determination of trace amounts of Zn(II)ions in water samples has been developed. The first additional carbonyl and carboxyl functionalized-nano graphene (SPFNano graphene). The presence of additional carbonyl and carboxyl groups located at the edge of the sheets makes GO sheets strongly hydrophilic, allowing them to readily swell and disperse in water. Based on these oxygen functionalities, different model structures of GO were used as absorbent for extraction of Zn (II) ions by solid phase extraction method. The complexes were eluted with HNO3 (2M)10% V.V-1 methanol in acetone and determined the analyte by flame atomic absorption spectrometry. The procedure is based on the selective formation of Zn (II) at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISKTM disks modified carbonyl and carboxyl functionalized-nano graphene oxide molecules covalently bonded together followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, SPFNano graphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be 456± 3 µg for Zn2+.The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of Zn in different water samples.