Applied Chemistry

A novel and selective method for the fast determination of trace amounts of Co(II)ions in water samples has been developed.  The first organic-solution-processable functionalized-Multiwalled carbon nanotubes (MWNTs) (SPFMWNTs) hybrid material with porphyrins. porphyrin–Multiwalled carbon nanotubes (MWNTs)  nanohybrid, 5-4 (aminophenyl)-10, 15, 20-triphenyl porphyrin and its photophysical properties including optical (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO- SPFMWNTs )were used as absorbent for extraction of Co(II)   ions by solid phase extraction method. The complexes were eluted with HNO₃ (2M)10% V.V^-1 mthanol in acetone and determined the analyte by flame atomic absorption spectrometry.  The procedure is based on the selective formation of Co(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 DISK^TM disks modified porphyrin–Multiwalled carbon nanotubes (MWNTs)  nanohybrid, 5-4 (aminophenyl)-10, 15, 20-triphenyl porphyrin (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO- SPFMWNTs ) 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, TPP-NHCO- SPFMWNTs, 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 600. The maximum capacity of the disks was found to be 568± 3 µg for Co²⁺. The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of Co in different water samples.

Interaction of various process parameters like initial chromium concentration (VI) (5-30 mg/l), pH (1-10), and adsorbent dosage (6-10 g/l) for chromium adsorption using custard apple powder were evaluated using central composite design (CCD) in response surface methodology. The CCD design in response surface methodology has been applied for designing the experiments as well as for full response surface estimation and 19 experimental data as per the model were used. The optimum conditions for better percentage removal of chromium from waste water with the concentration of 20 mg/l were as adsorbent dosage (9.9966 g/l), pH (2.7877) and initial chromium concentration (15.18693 mg/l). The high correlation coefficient (R2 =0.98929) between the model and the experimental data showed that the model was able to predict the better percentage removal of chromium (VI) from waste water using custard apple peel powder efficiently

A copper (II) complex, [cu(phen)(L-Ala)U](ClO4) (phen=1,10- phenanthroline, L-Ala =L-alanine,U =urea ), has been synthesized and characterized by Infra-red, EPR spectral and elemental analysis methods. The interaction with calf-thymus DNA has been studied by means of electronic absorption spectroscopy, emission spectroscopy, viscosity and cyclic voltammetry has been conducted to assess their interaction between their complex and DNA. A sample of copper II complex was tested for its Antimicrobial Activities and it was found to have good antimicrobial activities.

Thermo-chemically cracked cocos nucifera shells were converted into useful adsorbent using chemical activation method. Regeneration of the spent carbon was carried out via thermal regeneration method. The re-derived filter was used in the adsorption of nickel (Ni) from a simulated Ni2+ solution. Qualitative characterization was carried out using the Fourier Transformed Infra Red Spectrophotometer while Atomic Adsorption Spectrophotometer was used to analyze the equilibrium phase Ni2+ concentration. Comparative study of the derived and regenerated activated carbons was carried out using kinetic adsorption studies approach. From the experimental runs, it was evident that derived cocos nucifera shells activated Carbon provided slightly higher removal efficiency values than the vice for Nickel uptake. Investigations with applicability test supported the pseudo second order kinetics as best model in explaining the sorption rate (k2 = 0.744) as against the proposed linear and first order kinetics. Generally, reuse of spent coconut shell carbon and its investigated film diffusion transport mode in removal of Ni2+ is critical a study with a worthwhile adoption in remediation study.

Background: Iron oxide nanoparticles can be used for medical imaging, disease diagnosis, drug delivery, cancer treatment, gene therapy and other cases. These particles accumulate in liver cells and lead to oxidative stress with generation of reactive oxygen species. Aim: This study investigates the effect of iron oxide nanoparticles on liver tissue and enzymes [alanine aminotransfere (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP)] in male rat. Methods: 40 adult male rats of wistar strain, weighing 250-300 g were used for this study. The rats were randomly assigned to four groups. One group was control and other three groups were fed with iron oxide nanoparticles at 20, 50 and 150 µg/kg concentrations respectively for 15 days. Venous blood was taken to measure liver enzymes at the end of treatment. Liver of rats removed for histological experiments. Results: Significantly enhanced (P<0.05) AST level obtained as well as ALT and ALP level with used of maximum concentration of iron oxide nanoparticles (150 µg/kg) as compared to normal group. Conclusion: Based on our result, using high concentration of iron oxide nanoparticles could be caused undesirable effects on liver with damage to hepatocyte and level elevation of liver enzymes.

Mineral, physico-chemical, functional properties and fatty acid composition of Nigerian Periwinkle (Tympanotonus fuscatus var radula) were studied. The highest mineral in the sample was sodium with the value of 130mg per 100g while phosphorus had the lowest value of 2.18 mg per 100g. The refractive index was 1.46 and specific gravity was 0.89 g/cm3while the viscosity was 40.8 mPa/sec. Oleic acid had the highest value of 30.1% followed by Linoleic acid (27.9%) while palmitoleic acid (0.14%) was the lowest fatty acid in the sample.

The present paper is focused on the modification of the properties of polystyrene by adding cobalt chloride and manganese chloride. The composites are prepared using casting technique with different percentages of fillers. The experimental results show that the D.C conductivity of composites increases with the increase of cobalt chloride and manganese chloride concentrations. The D.C electrical conductivity changes with increasing of temperature. Also the activation energy of electrical conductivity of (PS-CoCl2) and (PS-MnCl2) composites decreases with increasing cobalt chloride and manganese chloride concentrations.

A simple method to pre-concentrated Citalopram on C18 modified carbon nanotubes in column has been applied as stationary phase which is used to measure the concentration of Citalopram in water samples by means of solid-phase extraction. To measure 250 mL water samples and 250mg C18 modified carbon nanotubes could be applied. Next step is to measure the Citalopram by injecting them to the gas chromatography with flame ionization. The advantages of applying HPLC with SPE in presence C18 modified carbon nanotubes are high sensitivity, High speed transformation of Citalopram and improving ration standard for river waters with Citalopram in the range of ppb or those with less than 10% of LOD. The quantity of extraction could be affected by sample's pH, amount of solvent, washing liquid type, solvent and flow rates of the sample solutions. The percentage recovery by SPE was 98.00 and the validation parameters proved the precision of the method and its applicability for the determination of citalopram in human plasma.

A copper complex of the type [Cu(Bipy)(L-Tyr)(TU)](ClO4), where Bipy = 2,2’ Bipyridine, Tyr = L-Tyrosine and TU = Thiourea, was synthesised and characterised by elemental analysis, UV-Visible, IR, conductivity measurement and EPR studies. DNA-binding properties have been studied by electronic absorption, emission, viscosity and cyclic voltammetric methods. The results suggest that the copper(II) complex bind to DNA via different modes. Gel electrophoresis study reveals the fact that the copper(II) complex cleaves super coiled pBR 322 DNA to nicked and slight linear forms in the presence and absence of ascorbic acid. The in vitro antimicrobial study indicates that the complex has good activity against gram positive, gram negative bacteria and fungus.

The reignited research on biodiesel production has witnessed, in recent decades, so much momentum to lead a great revolution in world energy in the near future. This great resurgence is stimulated in one part by the anxiety of the uncertainty of the supply life span of conventional fuels and in the other by the numerous advantages that biodiesel offer over petroleum diesel fuel. Biodiesel, amongst other benefits, is renewable, biodegradable, environmentally benign, energy efficient, and by far a major role-player in the league of biofuels that will sustain the energy future. Starting from history to present, this work presents a comprehensive review of major advance in biodiesel production. The five basic ways of making biodiesel: direct use and dilution, microemulsions, thermal cracking and transesterification are reviewed with emphasis on heterogeneous catalyst transesterification. Progresses in research into other methods such as enzyme catalysed, non-catalytic supercritical and ultrasound aided transesterification, biox co-solvent and in situ processes as well as production from microalgae are detailed. The factors affecting the yield of the different processes are identified and recommendations are presented for optimum production yield. Evaluation of the economic viability of biodiesel production shows the major challenges as the cost of production and limited availability of fat and oil resources. Microalgae prove to be the economical choice for biodiesel production, because of the availability, high productivity and low cost. Therefore, research should be geared towards the improvement and optimization of biodiesel production from algae.