Simple and sensitive differential pulse voltammetric (DPV) method has been developed for simultaneous determination of camylofin-2HCl and paracetamol. The electrochemical oxidation of camylofin was studied at carbon paste electrode using cyclic and differential pulse voltammetry. A reproducible and reliable oxidation current peak was obtained at pH 7. The oxidation current was enhanced in presence of sodium dodecylsulphate as an erosion reagent. Under optimal conditions the oxidation current was proportional to camylofin concentration in the range from 5.0 to 100.0 µM. Besides, the method was linear for paracetamol which is an active ingredient in the concentration range from 5.0 to 1000.0 µM. The proposed DPV method was selective for simultaneous determination of the two drugs with mean recovery of 99.58±2.13% and 99.44±0.57% for camylofin-2HCl and paracetamol, respectively. The method was validated according to ICH guidelines and successfully applied for the determination of the two drugs in combined pharmaceutical formulations.
Concentrations of heavy metals in water, sediments, as well as littoral plants from two sampling sites A and B of ijora creek of Lagos metropolis were investigated using Atomic Absorption Spectrophotometer. Water and sediments from site A showed higher concentrations of the investigated metals in them than those in site B. Mean values of the selected heavy metals recorded in sediments generally exceeded those in water samples. Some concentrations of heavy metals in the two littoral plants included: Pb (0.013mg/kg for Paspalum vaginatum); Cu in Philoxerus vermicularis for sites A and B were 0.47 and 0.40 mg/kg respectively while in Paspalum vaginatum, they were 0.59 mg/kg and 0.39 mg/kg respectively. Variations in concentration of Mn in Paspalum and Philoxerus site A ranged between 0.01 mg/kg and 0.08mg/kg. In Paspalum, values ranged between 0.02 and 0.06mg/kg. Nickel was not detected in both plant species from the two sites. The results showed that water and sediments in Ijora creek were contaminated with Pb, Cu, Mn and Ni while the plants were shown to have absorbed Pb, Cu, and Mn. It is assumable that anthropogenic activities around the creek contributed increased levels of heavy metals in the creek.
Pectin, a component of the plant cells, exists in the primary cell wall along with the middle lamella of plant tissues and is found mostly in citrus fruit peels. Peels of orange is an important source of pectin which is utilized as an emulsifying, gelling and thickening agent in varied food products. Currently, extraction of pectin is done through hot water at low pH for hours which is a time-consuming process. However, microwave extraction has verified to boost the pectin yield in lesser time. This study highlights the ability of microwave assistance in extraction of pectin from orange peels. Extraction of pectin was done with the varied combinations of microwave power (160, 320, and 480 W), microwave time (1, 2 and 3 min) and pH of citric acid solution (pH: 1, 1.5, 2). To analyze the outcome of microwave power, microwave time and pH on pectin yield, Box Behnken design of Response Surface Methodology was used. The optimized conditions, as per desired function test, determined for the peak pectin yield as 24.00% were; microwave power of 478 W, microwave time of 2.2 min and pH of 1.05. The validation test conducted on pectin extraction was found in acceptance with the optimized conditions.
Aims: The aim of this work is to investigate the inhibitive properties of Azadirachta indica (neem) gum on mild steel corrosion in different acidic media using gravimetric method.
Place and Duration of Study: Chemistry Laboratory, Department of Chemistry, Kano University of Science and Technology, Wudil, between January 2018 and March 2018.
Methodology: Gravimetric method was used to analyse the effectiveness of Azadirachta Indica (AZI) gum as a mild steel corrosion inhibitor in 1.0M nitric acid (HNO3), sulphuric acid (H2SO4) and hydrochloric acid (HCl) solutions at 298K and 313K. Weight loss was obtained at different concentrations of the inhibitor; 0.50, 1.00, 1.50, 2.00 and 2.50% w/v. From the weight measurements, the degree of surface coverage and inhibitor efficiency were computed. The activation energy was calculated using the Arrhenius equation, and Gibbs free energy and heat of adsorption were determined to study the spontaneity and enthalpy of the corrosion process. Adsorption isotherms; Langmuir, Temkin and Fraudlish were employed in order to have insight into the possible mechanism of adsorption involved.
Results: Gravimetric measurements of pure solvents used at several concentrations (0.5, 1, 1.5 and 2 M) showed that weight loss increases with temperature and concentration of the acids. When different concentrations of inhibitor were introduced into the solvents, a similar trend was observed. Inhibitor efficiency increases with temperature and with concentration of the inhibitor. H2SO4 was found to have the highest inhibition efficiency of 89.93% and 95.82% at 298K and 313K respectively in 2.5%w/v concentration of the inhibitor. Its strong hydrogen bonding and high surface tension may be a contributing factor. Corrosion rate was calculated and HNO3 was found to be more corrosive than HCl and H2SO4 both in the presence and absence of the inhibitor at 298K and 313K.
Conclusion: From the study, Azadiracta indica gum was found to retard corrosion of mild steel. HNO3 acid was more aggressive and has the highest corrosion rate. Therefore corrosion retardation in this medium was least effective. This might be attributed to the strong oxidising ability of HNO3 than HCl and H2SO4. The rate of corrosion was more retarded in H2SO4. Free energy of the process was negative all through the inhibitor concentrations indicating that the action of the inhibitor on the metal surface was spontaneous. Data of the corrosion process also fitted well in to Langmuir isotherm suggesting that the mechanism of corrosion could be predominantly physisorption.
Honey is a natural food is produced from the nectar of flowers by bees, contains a lot of sugars, vitamins, minerals and nucleic acids. Honey is an important nutrient for the human body and health, where modern science proved that honey natural antibiotic and tonic for the human body. This study will determine the physicochemical properties such as electrical conductivity, pH and free acidity for different types of honey on the market in Saudi Arabia. Four types of honey were selected randomly sidr, buckwheat, clover and cotton. Electrical conductivity was found to be 0.680±0.000, 0.434±0.001, 0.217±0.000 and 0.199±0.001 mS/cm for sidr, buckwheat, clover and cotton, respectively. On the other hand, the pH measurements were found to be 5.6±0.03, 4.73±0.01, 4.51±0.01 and 4.49±0.02 for sidr, buckwheat, clover and cotton, respectively. Finally, the free acidity was determined by volumetric titration and was found to be 12±0.02, 14.7±0.6, 10.7±0.6 and 8.7±1.2 meq/kg. However, the potentiometric titration method gives 9.9±0.3, 10.9±2.5, 9.9±0.4and 6.2±0.6 meq/kg for sidr, buckwheat, clover and cotton, respectively. The conductivity and acidity were compared with the limited range in the codex Alimentarius and found to be in the range.