Determination of methyl mercury in biological samples from Dakar coast using CV-AAS and a simple ultrasound method

Ndiaye Birame , Ndiaye Momar , Diop Abdoulaye and Benita Pérez Cid

The ultrasound-assisted extraction method proposed in this work was applied to the determination of methyl mercury in biological samples (wild fish species and mussels) from the Dakar coast (Senegal) using Cold Vapor Atomic Absorption Spectrometry (CV-AAS). Microwave acid digestion was also employed for total mercury determination. Dakar coast usually receives numerous domestic and industrial discharges without prior treatment; however, no research works were developed to evaluate mercury accumulation in marine biota. Total mercury contents in mussels (between 0.0355-0.1206 μg/g) were considerably lower than that found in fish species (between 0.2560-0.8940 μg/g). In all cases, the values obtained were always lower than the European legislation limits for fish and seafood products. The contents of methyl mercury were, in all cases, lower than total mercury and a satisfactory correlation (p <0.0001; r= 0.999) was obtained between them. A reference material (DORM-2) was used to validate the two analytical procedures used for sample preparation.

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Extraction and Separation of Thorium (IV) using Dibenzo-18-Crown-6 in Xylene

Mohite B. S. and Madane N. S.

A simple and selective method for the extraction and separation of thorium (IV) from L-histidine medium using dibenzo-18-crown-6 in xylene has been developed. Thorium (IV) was quantitatively extracted by 5x10-4M dibenzo-18-crown-6 in xylene from 5x10-4M L-histidine medium. The extracted thorium (IV) was stripped out quantitatively from the organic phase with 6 M nitric acid and determined spectrophotometrically with arsenazo (III) at 620 nm. The effect of concentrations of L-histidine, extractant, diluents, metal ion and strippants has been studied. The tolerance limits of various cations and anions were studied. Separation of thorium (IV) from other elements was achieved from binary mixtures. Using this method separation and determination of thorium (IV) in geological and real samples has been carried out. The method is simple, rapid and selective with good reproducibility (approximately ± 2%).

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The effect of activation method on the adsorption performance of saw-dust activation carbon

Attia Amina A., Aboelenin Reham M.M., Soheir A. Kheder, Ghada Mohmed M. and El-Shafey Shaymaa E.

The adsorption abilities of saw dust after thermal and chemical treatment were investigated for its efficiency in removing para-nitro phenol (PNP) from aqueous solution. Batch adsorption studies were carried out under varying conditions of initial pH, contact time and temperature. The performance of saw dust activated carbons was characterized by BET surface area, Fourier Transform Infra Red spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The Langmuir, Freundlich and Temkin models were used to describe the adsorption equilibrium studies of saw dust activated carbon. Langmuir isotherm shows better fit than Freundlich and Temkin isotherm. Three simplified kinetic models including pseudo-first order equation, pseudo-second order equation and intra-particle diffusion model were selected to follow the adsorption process. Based on this study, the thermodynamic parameters like standard Gibb’s free energy (ΔG˚), standard enthalpy (ΔH) and standard entropy (ΔS˚) were calculated. The obtained results show that the adsorption of PNP onto saw dust activated carbon samples was of physical in nature, spontaneous exothermic and followed second rate kinetic.

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Physico-chemical properties and protein profiling of gum exudates of Acacia nilotica collected from different agro-climatic zones in India

Siddiqui Mahtab Zakira, Thamilarasi K. and Singh Bhoj Raj

Physico-chemical properties and protein profiling of seventeen Acacia nilotica (babool) gum exudates collected from ten Indian States covering five agro-climatic zones of India were studied to find out the intra-specific variations in their moisture level, total color difference (ΔE), yield %, ash content, elemental level, tannin content (mg/g), specific rotation [], swelling index (%, v/v), viscosity and FT-IR. All the gum exudates showed Newtonian behavior with viscosity being shear rate independent. Gums were thermally characterized using differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA). DSC thermogram of gum samples showed presence of a broad endothermic peak at around 90-130 0C and occurrence of glass transition temperature in the range of 60.82-68.62 0C. TGA analysis showed three phases of weight loss indicating that the gum is thermally relatively stable. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of gum samples showed presence of mainly low molecular weight proteins. The observed intra-specific variations in the properties of Acacia nilotica gum exudates collected from different agro-climatic zones of India are presumably due to the effects of difference in their geographical locations, edaphic conditions, climatic factors, botanical sources, season and the age of the tree etc.

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Hydrogeochemistry of Lentic Ecosystem in the Mysore City

Padmanabha B.

The major ion concentration data has been processed using the HYCH- basic Computer programme. In this computer programme, the estimation of Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Corrosivity Ratio (CR), USSL classification of water for salinity and sodium hazards and Permeability Index (PI) are employed. This study suggests that Sodium Percentage, Residual Sodium Carbonate (RSC) recorded higher in the Kamana lake than in the Dalvoi lake. Sodium Adsorption Ratio and Corrosivity ratio documented higher in Dalvoi lake than Kamana lake. The water of Kamana lake is non-corrosive and in Dalvoi lake it is corrosive. According to USSL classification, the water of these two lakes indicated low salinity with high or very high sodium hazard. Permeability index recorded higher in the Kamana than in the Dalvoi lake. Permeability index documented highest during winter season followed by monsoon and lowest in the summer season. Influx of large quantity of domestic sewage decreased water level and increased dissolved solids might have decreased the permeability index in the summer season.

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Copper sulphate induced histopathological alterations in organs of Ariopsis seemanni (Colombian Shark Cat Fish)

Thyagarajan R., Narendrakumar G., MasilamaniSelvam M. and Rameshkumar V.

The effect of copper sulphate on liver, gills and muscles of fish Ariopsis seemanni was observed as metabolic indicators. The fish was exposed to sub-lethal concentrations of copper sulphate for 5, 10 and 15 days at 2 ppm, 4 ppm and 6 ppm. The histopathological study on the gills, liver and muscles was also done in order to determine the tissue damage. These findings suggest significant increase of transaminase activity while reduced amount of carbohydrates and protein content might be the consequence of tissue damage in Ariopsis seemanni.

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RP-HPLC Method Development and Validation for Antihypertensive Drugs

Kabra Prachi, Nargund L.V.G. and Murthy M. S.

This study proposes a liquid chromatography (RP-HPLC) method for quantitative analysis of Amlodipine besylate, Hydrochlorothiazide and Olmesartan medoxomil in tablet dosage form in presence of paracetamol as an internal standard. The chromatography was performed on a Gracesmart C18 column (5 μm, 250 mm×4.6 mm i.d.) using the mixture of acetonitrile and 10 mM potassium dihydrogen phosphate buffer in the ratio 40:60 %v/v as mobile phase. The pH of buffer was adjusted to 3.0 with 1% o-phosphoric acid. Flow rate was maintained at 1.5 ml/min and analytes were detected by measuring the absorbance at 238 nm using UV detector. Paracetamol, Hydrochlorothiazide, Amlodi- pine and Olmesartan were eluted at 1.93, 2.26, 3.58 and 6.78 min respectively. The method was linear in concentration range of 25-625 µg/ml, 62.5-153.5 µg/ml and 100-2500 µg/ml for Amlodipine besylate, Hydrochlorothiazide and Olmesartan medoxomil respectively. Mean % assay of Amlodipine besylate, Hydrochlorothiazide and Olmesartan medoxomil was observed as 99.68 %, 101.13 % and 100.86% respectively. The method was validated in accordance with ICH norms and method was found to be specific, accurate, precise and easy to use for routine analysis.

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Solvent free synthesis and DNA photocleavage study of 3-aryl/heteroaryl-9-methyl-1,2,4-triazolo[4,3-α]quinolines

Kumar Mohit, Kumar Vinod and Beniwal Vikas

A mild and efficient synthetic route has been developed for the preparation of some biologically important 1-aryl/heteroaryl-5-methyl-1,2,4-triazolo [4,3- α] quinolines in excellent yields. In this approach, various quinolinylhydrazones were ground at ambient temperature using iodobenzene diacetate (IBD) under eco-friendly conditions. Therefore, we report a green, rapid and efficient protocol for the synthesis of triazoloquinoline derivatives. The synthesized compounds were characterized on the basis of their FT-IR, 1H NMR spectral data and by comparing their melting points with those reported in literature. Further all compounds were evaluated for their DNA photocleavage activity and it has been observed that compounds 2a-f, 2h-j and 2l displayed good level of biological potential.

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Effect on other water parameters on defluoridation by N-N-dimethylamine N-ethylamine Chitosan

Aswar Sachin Arunrao, Yeul Vijay S. and Pundlik Rambhau Bhagat

This study is intending to examine the effect on other water parameters on fluoride removal by using N-N-dimethylamine N-ethylamine Chitosan. For this intention, a number of water parameters including initial pH, conductivity, sodium, fluoride, chloride, sulphate, nitrate etc. were studied. From the results it is concluded that N-N-dimethylamine N-ethylamine Chitosan can significantly remove the fluorides from water and it would not affect the other parameters of water to the extent.

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Ultraviolet-visible spectroscopic method in determining reaction rate constant for the reduction of Cr (VI) to Cr (III) using ferrous sulphate

Jose S. Hilario and Antonio G. Celajes Jr.

The kinetics of the reduction of hexavalent to trivalent chromium using ferrous sulphate (FeSO4) under acidic condition was studied using two methods of UV-Visible spectroscopy – the HACH and the Lambda Series. Potassium dichromate (K2Cr2O7) was used as source of Cr6+. Due to complexity and time consuming steps of the Lambda Series, the HACH Method was employed as screen test. As soon as the trial gave good results from the HACH method, the Lambda series was performed. Comparison of the results was carried out and several differences were noted. The study was composed of four parts – kinetics of the reduction of potassium dichromate by ferrous sulphate, determination of the rate and order of reaction, analysis of chromium hexavalent using the Diphenylcarbazide Method of HACH and Lambda Series UV-Vis spectrometer and determination of rate constant. There are several trials performed to arrive at the procedure for the reduction of hexavalent chromium via ferrous sulphate presented herein. Same is true with the rate and order of reaction. At a ratio of 1:10 of potassium dichromate to ferrous sulphate, a good result for the rate and order of reaction was obtained. Results from the procedures showed that the overall rate of reaction is first order – that is zero order with respect to K2Cr2O7 and first order with respect to FeSO4. In the kinetic study, a ratio of 3:5 K2Cr2O7 to FeSO4 also showed good results in which the rate constant was computed to be 1.7 x 10-4 per second. However this result was only obtained from the HACH Method. Lambda Series showed different results in the computation of rate constant.

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