فهرست مطالب

Journal of Chemical Health Risks
Volume:3 Issue: 3, Summer 2013

  • تاریخ انتشار: 1392/09/18
  • تعداد عناوین: 8
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  • A. Moghimi, S. Yousefi Siahkalrodi Page 1
    A novel, simple, sensitive and effective method has been developed for preconcentration of lead. This solid-phase extraction adsorbent was synthesized by functionalization of graphenes with covalently linked N-methyl-glycine and 3, 4-dihydroxybenzaldehyde onto the surfaces of graphite. The method is based on selective chelation of Pb (II) on surfactant coated C18, modified with functionalization of graphenes (graphene-f-OH). The adsorbed ions were then eluted with 4 ml of 4 M nitric acid and determined by flame atomic absorption spectrometry (FAAS) at 283.3 for Pb. The influence of flow rates of sample and eluent solutions, pH, breakthrough volume, effect of foreign ions were investigated on chelation and recovery. 1.5 g of surfactant coated C18 adsorbs 40 mg of the functionalization of graphenes (graphene-f-OH) base which in turn can retain15.2±0.8mg of each of the two ions. The limit of detection (3σ) for Pb(II) was found to be 3.20 ng l -1. The enrichment factor for both ions is 100. The mentioned method was successfully applied on the determination of Pb in different water samples.
  • R. Kazemi Darsanaki, M. Mohammad Doost Chakoosari, M. Azizollahi Aliabadi Page 13
    Mycotoxins are secondary metabolites of molds and have adverse effects on humans, animals, and crops. Those can cause illnesses and economic losses. Aflatoxin M1 (AFM1) is one of the mycotoxins produced from the hydroxylated metabolite of aflatoxin B1 (AFB1). It can be found in milk or milk products obtained from livestock that have ingested contaminated feed. In this paper, recent studies were reviewed in aflatoxin M1 contamination in milk and milk products in Iran.
  • R. Nassiri, A. Mohammadinafchi Page 21
    The effects of nano titanium dioxide incorporation were investigated on the water vapor permeability, oxygen permeability, and antimicrobial properties of bovine gelatin films. The nano TiO2 (TiO2- N) was homogenized by sonication and incorporated into bovine gelatin solutions at different concentrations (e.g. 1, 2, 3, and 5% w/w of dried gelatin). The permeability of the films to water vapor and oxygen was significantly decreased by incorporating of low concentration TiO2-N to gelatin solutions. TiO2-N gelatin films showed an excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. These properties suggest that TiO2-N has the potential as filler in gelatin-based films for using as an active packaging materials in pharmaceutical and food packaging industries.
  • J. Abolhasani, M. Amjadi, E. Ghorbani Kalhor Page 29
    A sensitive, selective and effective ionic liquid-based single drop microextraction technique was developed by using ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate, C MIMPF6, coupled with electrothermal atomic absorption spectrometry (ETAAS) for the determination of copper and silver in environmental samples. Dithizone was used as chelating agent. Several factors that influence the microextraction efficiency and ETAAS signal, such as pH, dithizone concentration, extraction time, amounts of ionic liquid, stirring rate, pyrolysis and atomization temperature were investigated and the microextraction conditions were established. In the optimum experimental conditions, the detection limits (3 s) of the method were 4 and 8 ng L-1 and corresponding relative standard deviations (0.1 μg L-1, n = 6) were 4.2% and 4.8% for Ag and Cu, respectively. The developed method was validated by analysis of a certified reference material and applied to the determination of silver and copper.
  • M. Rojhan, L. Nouri Page 43
    Starch is found in abundance in nature and it is one of the raw materials used for food packaging because of the low price, biodegradability, good mechanical and barrier properties. The recycling ability of coating materials was significantly increased by using edible films and coating in comparison to traditional packaging and it could be an alternative for synthetic films. In this research, the effect of eucalyptus extract (Aqueous Extract) was investigated on tapioca starch films. Tapioca starch films were prepared by casting method with addition of eucalyptus extract and a mixture of sorbitol/glycerol (weight ratio of 3 to 1) as plasticizers. Eucalyptus extract incorporated to the tapioca starch films were dried at different concentrations (0, 15, 25, and 35 of total solid) under controlled conditions. Physicochemical properties such as water absorption capacity (WAC), water vapor permeability (WVP) and mechanical properties of the films were evaluated. Results showed that by increasing the concentration of eucalyptus extract, tensile strength was increased from 20.60 to 15.68 (MPa), also elongation was increased from 19.31 to 23.57 (%) at break and Young’s modulus was decreased from 800.31 to 500.32 (MPa). Also incorporation of eucalyptus extract in the structure of biopolymer increased permeability of water vapor of starch films. Tapioca starch films incorporated with eucalyptus extract exhibited excellent antimicrobial activity against E. Coli. In summary, eucalyptus extract improves functional properties of tapioca starch films and this types of films can be used in food packaging.
  • Z. Alishavandi, N. Mosallanejad, R. Shabani Page 53
    In this study, a new adsorbent, silver nanoparticle loaded on activated carbon (Ag˗NP˗AC) was used for removal of acid yellow199 (AY 199) dye. This novel material was characterized and identified by different techniques such as Brunauer, Emmett and Teller (BET), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis. Unique properties of this adsorbent such as high surface area (>1100 m2g-1) and low pore size (<47 A˚) and average particle size lower than 60 A˚ make it possible for efficient removal of Ay199. In batch experimental set-up, adsorbent dosage, initial dye concentration, contact time and pH were investigated. Optimum values were set as pH of 3.0, 0.03g/50mL of adsorbent for initial dye concentration of 15 mgL-1 at 40 min and 25 ±1 ºC. The adsorption of Ay199 follows the pseudo-second-order rate equation in addition to interparticle diffusion model (with removal more than 90%) at all conditions. Equilibrium data fitted well with the Langmuir model, while maximum adsorption capacity was 30 mg g-1 for 0.03 g/50mL of Ag˗NP˗AC. Calculation of various thermodynamic parameters such as, Gibb’s free energy, entropy and enthalpy of the on-going adsorption process also indicated feasibility and endothermic nature of AY 199 adsorption onto Ag˗NP˗AC.
  • M. Ahmadi, Z. T. Alipour, A. Farrokhian Firuzi Page 69
    Polycyclic Aromatic Hydrocarbons (PAHs) are one of the most important organic pollutants frequently found in the environment. In this experiment, the effect of phytoremediation as a cost effective method was studied on the concentration of anthracene (C14H10) which is one of PAHs. The effect of sorghum (V1), hairy vetch (V2) and oat (V3) was studied under four concentrations of anthracene (S1, S2, S3 and S4) in soil. In S1 level which pollution was the lowest, the three plants had the highest reduction rate. The reduction rate was decreased by increasing the pollution level (S2 and S3),; the lowest reduction rate was observed in S4 level which had the highest pollution level. There was significant difference between the three plants and the fallow. Generally, hairy vetch had the highest phytoremediating capacity and resistance compared with the other plants.
  • A. Pacheco Ferreira Page 77
    The aim of this study was to survey levels of polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dibenzo-p-dioxins (PCDDs) in white mullet (Mugil curema), common snook (Centropomus undecimalis), and acoupa weakfish (Cynoscion acoupa), collected at Sepetiba bay, Rio de Janeiro, Brazil, March-August 2013. PCBs and PCDD/Fs were determined by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS) as stated by the US EPA 1613B, 1668B, and 8290A methods. The concentration of total PCBs ranged from 0.589688 ~ 0.6981629 pg-WHO-TEQ/g ww and PCDDs/PCDFs ranged from 0.134037 ~ 0.242573 pg-WHO-TEQ/g ww. The concentrations of these contaminants on fish species currently appear to fall below critical values, and the dietary consumption of these species did not represent a risk for human health. However, seeking to avoid future problems, systematic monitoring can prevent complications to the environment, marine wildlife and public health impacts.