[Show abstract][Hide abstract] ABSTRACT: Utilization of synthetic acaricides causes negative side-effects on nontarget organisms and environment and most of themite species such as two spotted spidermite, Tetranychus urticae Koch, are becoming resistant to these chemicals. In the present study, essential oils of fennel, Foeniculum vulgareMill., and lavender, Lavandula angustifoliaMiller, were hydrodistilled using Clevenger apparatus and chemical composition of these oils was analyzed by GC-MS. Anethole (46.73%), limonene (13.65%), and 𝛼-fenchone (8.27%) in the fennel essential oil and linalool (28.63%), 1,8-cineole (18.65%), and 1-borneol (15.94%) in the lavender essential oil were found as main components. Contact and fumigant toxicity of essential oils was assessed against adult females of T. urticae after 24 h exposure time.The essential oils revealed strong toxicity in both contact and fumigant bioassays and the activity dependeds on essential oil
concentrations. Lethal concentration 50% for the population of mite (LC50) was found as 0.557% (0.445–0.716) and 0.792% (0.598–1.091) in the contact toxicity and 1.876 𝜇L/L air (1.786–1.982) and 1.971 𝜇L/L air (1.628–2.478) in the fumigant toxicity for fennel and lavender oils, respectively. Results indicated that F. vulgare and L. angustifolia essential oils might be useful for managing of two spotted spider mite, T. urticae.
[Show abstract][Hide abstract] ABSTRACT: The major constituents of the oil of Lavandula angustifolia Mill were estimated as borneoll (8.57%), alpha terpinene (6.22%), linolool (4.91%) geranyl proprionate (3.76%), butanoic acid hexyl ester (2.99%) and caryophyllene oxide (2.72%). LC10, LC30 and LC50 were estimated as 0.31%, 0.705% and 1.24% respectively. The sublethal concentration (LC30) of essential oil affected the nutritional indices of 4th instar larvae of Glyphodes pyloalis. The essential oil reduced total protein, carbohydrate and lipid when compared with the control. All concentrations (0.25%, 0.5%, 1%, and 2%) of essential oil affected the major macromolecules and activities of key enzyme in G. pyloalis.
Pesticide Biochemistry and Physiology 10/2013; 107(2):250–257. · 2.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This investigation involved electrochemical synthesis of a new Ni(II) selective chelating agent by electropolymerization of 4-nitrophenol in acetate medium. The prepared polymer was characterized by FT-IR, 1H-NMR, CHNO elemental analysis, GPC, and UV-Vis spectrometry and a suitable chemical structure was suggested. This new ligand was successfully applied in cloud point extraction (CPE) of Ni(II) before flame atomic absorption spectrometry (FAAS) measurements. The pH and the concentration of the phosphate buffer, chelating agent, surfactant and salt were optimized. In the presence of foreign ions, no significant interferences were observed. Under optimum conditions, the limits of detection (LOD) and quantification (LOQ) were 0.76 and 2.53 ng mL−1, respectively. The mean, preconcentration factor, standard error and RSD for five replicates of 10 ng mL−1 Ni(II) were calculated to be 9.78 ng mL−1, 29.3, 2.2% and 3.36%, respectively. The method presented good sensitivity and selectivity and was applied for the determination of trace amounts of Ni(II) in various water and wastewater samples. The results obtained by the proposed method were in good agreement with the results of inductively coupled plasma-optical emission spectrometry (ICP-OES).
[Show abstract][Hide abstract] ABSTRACT: A pencil graphite electrode coated by copper (II)–carmoisine dye complex in polyaniline (emeraldine base form) matrix (termed
as PGE/PA/Cu-Car) was prepared and used as copper ion-selective electrode. The introduced electrode was found to have high
selectivity toward copper ion (II) and exhibited wide working concentration range, low response time, and good shelf life.
The sensor electrode showed a linear Nernstian response over the range of 5.0 × 10−6 to 1.0 × 10−1 M with a slope of 29.7 ± 1 mV per decade change in concentration. A detection limit of 2.0 × 10−6 M was obtained. The optimum pH working range of the electrode was found to be 4.0–7.0.
Journal of Solid State Electrochemistry 01/2012; · 2.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The high tendency of 5-nitropiazselenol for self-accumulation on thin mercury film electrode was used innovatively for determination of Se(IV) in natural waters. 5-Nitropiazselenol was formed by reaction between Se(IV) and 4-nitro-1,2-phenylenediamine in acidic solution and self-accumulation process was carried out directly from reaction media. The adsorbed 5-nitropiazselenol was stripped in HCl solution by DP cathodic potential scan. All parameters influencing the measurement were optimized and evaluated. Detection limit of this method is 0.06 ng mL(-1). Interferences of various cations and anions were studied. The adsorption tendency of some other piazselenols made by some aromatic ortho-diamines was also investigated. The problems arising from applying potential during accumulation process in natural waters analysis were discussed. This method was applied for determination of Se(IV) in natural waters collected from some internationally registrated lagoons south of Caspian Sea. The obtained results were compared with the results of ICP-AES and DPCSV after electrochemical preconcentration.
Journal of hazardous materials 09/2009; 174(1-3):788-94. · 4.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this work bovine albumin was used innovatively as a medium for adsorptive accumulation of Se-I(2) on thin mercury film electrode. Se-I(2) was formed by reaction between Se(IV) and iodide in HCl media. The adsorbed Se-I(2) was stripped in 0.05 M HCl by differential pulse cathodic potential scan. The proposed method was successfully applied to analysis of Se(IV) and Se(VI) in natural waters sampled from some lagoons south of Caspian Sea. The optimum reaction conditions and other analytical parameters and influence of cations and anions were studied. The detection limit was 0.37 ng mL(-1). The obtained results were compared with the results of DPCSV after electrochemical preconcentration, HG-AAS and ICP-AES.
Journal of hazardous materials 03/2009; 168(1):542-7. · 4.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The chemical composition of worm wood Artemisia annua L. (Astraceae), a medicinal plant, was studied by gas chromatography and gas chromatography- mass spectrometry (GC-MS). About 60 compounds were identified, from which the major compounds were erythritol (50.30%), camphore (7.25%), pinocarveol (4.13%) and diethoxyethane (2.18%). The effect of crude extract on deterrency was maximal in 1000 μL/L treatment (only 4.66 ±1.05 insects were attracted to treated food) compared to control (12.6 ±0.96) The growth regulatory effect showed that 1600 μL/L treatment variously affected the weight of larvae, pupae and adult (0.48 ±0.003, 2.17 ±0.02 and 1.31 ±0.015, respectively) and finally the ovicidal effect and the number of adults appearing in F1 were similarly affected (38.5 ±1.7 and 33.75 ±2.31), comparing to control (99.25 ±1.727 and 92.5 ±1.35). The present result and previous results on this plant species indicate that it can be a good candidate for controlling stored product insects.