Volume-13 ~ Issue-5 ~ May 2020

Abstract: This research highlights the benefit of using the mixture of two fluxes, NH4HF2-KOH during the fusion and in the optimization of the water leaching parameters of niobium and tantalum contained in the Manono ore in the Republic Democratic of Congo. The ore studied is a columbite containing approximately 53% in Nb2O5, 30% in Ta2O5, 7% in SiO2, 5% in SnO2 and 3% in Fe2O3. Indeed, the use of ore/ NH4HF2/KOH charge in a respective mass ratio of 1,0 /2,5 / 1,0 has an advantage insofar as the better efficiency of leaching water with niobium and tantalum are respectively obtained at approximately 97% and 94% at 160°C for 90 minute of fusion and 30 minutes of agitation leaching against 89% and 84% when NH4HF2is used alone at 250°C. This advantage comes from the fact that the addition of KOH to the ore/NH4HF2 mixture causes a spontaneous and exothermic reaction.

Key Word: leaching parameters; tantalum niobium; fusion system; NH4HF2-KOH

[1]. Albert C., and Geoffrey W., (1980) Advanced Inorganic chemistry, John wiley and son, New York, p393-394, 752-765
[2]. AnatolyA., (2004). The chemistry of tantalum and niobium fluoride compounds. Elsevier p1-2, 157-149, 409
[3]. Dewaele S., et al (2015). Géological setting and teming of world class Sn, Nb-Ta and Li mineralization of Manono-Kitotolo Katanga, Democratic Republic of congo. Ore Geology Reviews pp 373-385.
[4]. Eckert J., (1995). Hydrometallurgical processing of Ta/Nb compounds. Present state of the art. Processings of international symposium of tantalum and niobium, Germany. Tantalum –niobium international study center, Belgium, pp 51.
[5]. Kabangu M., (2013). Extraction and separation of tantalum and niobium from Mozambican tantalite by solvent extraction in the ammonium bifluoride-octanol system, University of Prectoria p1-44.

Abstract: Background: Cholesterol is subsumed a seminal lipid molecule in cell membranes and lipoprotein, vital for normal body function except at abnormal levels, as these have precipitated different human diseases including stroke, heart diseases and brain diseases. As a result, accurate measurement of cholesterol is pivotal particularly for people at high risk for the aforementioned diseases. This study investigates the cholesterol status in milk, egg, and cod liver oil samples obtained from different locations in Osogbo metropolis, Osun State, Nigeria. Fourier Transform Infrared (FTIR) spectrophotometer was used for identification of the functional groups in the samples while the cholesterol contents were determined using Ultraviolet (UV) spectrophotometer......

Key Words: Cholesterol; Cod liver oil; Milk; Egg; FTIR; UV spectrophotometer

[1]. Osman, H. and Yap, K.C. (2006) Comparative Sensitivities of Cholesterol Analysis Using GC, HPLC and Spectrophotometric Methods. The Malaysian Journal of Analytical Sciences, 10(2), 205-210.
[2]. Maekawa, M. and Fairn, G.D. (2015) Complementary probes reveal that phosphatidylserine is required for the proper transbilayer distribution of cholesterol. J Cell Sci, 128, pp. 1422-1433.
[3]. Norum, K.R., Berg, T., Helgerud, P. and Drevon, C.A. (1983) Transport of cholesterol. Physiol Rev, 63, pp. 1343-1419.
[4]. Park, J.-M, Jeong, I.-S, Kwak, B.-M, Ahn, J.-H, Leem, D., Jeong, J. et al. (2013) Application of rapid sample preparation method and monitoring for cholesterol content in chicken egg and egg powder. Korean J Food Sci Anim Resour, 33, pp. 672-677
[5]. Boyer, J.L. (2013) Bile formation and secretion. Compr Physiol, 3, pp. 1035-1078

Abstract: In recent times there has been an upsurge in the search for new chemical agents to replace the conventional drugs, which have been characterized by drug resistance of microbes and the deleterious side effects associated with them. The use of any plant as medicine is attributed to its biological activities. Pterocarpusmildbreadii is a medicinal plant belonging to the family fabaceae, that abounds in Ghana, with its potentials yet to be explored. The present work aimed at screening the stem bark extracts of the variety of P. mildbreadii in Kumasi, Ghana, for their phytochemical constituents, antimicrobial and antioxidant activities aimed at finding future sources of antibiotics and antioxidants for pharmaceutical formulations. The antimicrobial efficacy was evaluated by the agar diffusion method, using Augmentin as standard; while antioxidant potential was assayed using 2,.....

Keywords: Pterocarpusmildbreadii, antioxidant activity, DPPH, antimicrobial activity, H2O2

[1]. T. Roger, M. Pierre-Marie, VK. Igoh, VD. Patrick, "Phytochemical screening andantimicrobialactivity of medicinal plants used to treat typhoid fever in Bamboutus Division," West Cameroon. Journal of Applied Pharmaceutical Science. Vol. 5(6):34-49, 2015.
[2]. Abubakar, B.A; Aliyu, MM; Miklai S.A; Hamisu, I; Adebayo, O, "Phytochemical screening and antimicrobial activities of Vernoniaambigua, vernonablumeodes and Vernoniaoocephala" Natural drugs. 68(1): 67-73, 2009.
[3]. Catteau, L; Bambeke, F.V; Quetin-Leclercq, J,"Preliminary evidence of the direct antimicrobial activity of 12 plants used in traditional medicine in Africa,"Phytochem. Rev.vol 14: 975-991, 2015.
[4]. Ellen MDB, Tamires GDB, Adriel SDDC, Marcos DCS, Edson DJM, Vera LCV,"Antimicrobial, Antioxidant and cytotoxic activities and chemical profile of species of miconia Ruiz and Rav. Clindemia D.Don and TibouchinaAubl( Melastomataceae)," Journal of medicineal plants Research .14(1):1-6, 2020.
[5]. Ogukwe, CE; Oguzie, Unaegbu, C; Okolue, BN, " Phytochemical screening in the leaves of Sansevieraifasciata." J. Chem. Sci. Nigeria 29: 8-9, 2004.

Abstract: Background: Mangiferaindica L. and Persea Americana L. are two fruit trees very well-known and appreciated by the people of Benin for their fruits. The seeds from the fruits of these plants, despite their growing interest in pharmacology, are considered as environmental waste not yet recovered. This work aims to determine the phytochemical composition and the antimicrobial activity of the ethanolic extract of these two neglected seeds in Republic of Benin. Materials and Methods:50 g of powder of P. Americana and M. indicaseeds were separately crushed and recovered in 500 ml of ethanol 96°C to obtain their extracts. The qualitative and quantitative phytochemical screening was performed to determine the different phytochemical groups. Antimicrobial activity was performed on eleven bacteria to determine theinhibitory diameter zone, the Minimum Inhibitory Concentrations and the inimum Bactericidal Concentration.....

Keywords: Mangiferaindica, Persea Americana, seeds, phytochemical composition, Antimicrobial tests.

[1]. Awad El-Gied AA, Joseph MRP, Mahmoud IM, Abdelkareem AM, Al Hakami AM, Hamid ME. Antimicrobial Activities of Seed Extracts of Mango (MangiferaindicaL.).Advances in Microbiology: 2012; 2: 571-576.
[2]. Marjorie MC. Plant Products as antimicrobial Agents. Clinical and Microbiology Reviews. 1999; 12: 564-582.
[3]. Ahmed I, Beg AZ. Antimicrobial and phytochemical studies on 45 Indian medicinal plants. Journal of Ethnopharmacology2001; 74(2):113-123
[4]. Singh M, Khatoon S, Singh S, Kumar V, Rawat AK, Mehrotra S. Antimicrobial Screening of Ethno- bo-tanically Important Stem Bark of Medicinal Plants. Pharmacognosy Research. 2010; 2: 254-257.
[5]. Sofowora A. maedicinal plants and traditional Medicine in Afric, John Wiley and Sons Ltd., New York, 1982

Abstract: A simple hybrid flow system is proposed for the determination of N-acetyl-L-cysteine based on the reaction between copper(II)-neocuproine and N-acetyl-L-cysteine, yielding an orange-yellow copper(I)-neocuproine complex with absorption maximum at 458 nm. The method involved injection of approximately 300 μL of sample/standard and 300 μL reagent solution simultaneously. The optimum conditions were evaluated, calibration curve was linear over the range of 1.0×10–6 - 1.0×10–4 mol L–1 of N-acetyl-L-cysteine with detection limit of 2.7 × 10–7 mol L–1. A sample throughput of 100 h−1 was obtained. This hybrid flow technique was found to be simple, accurate, reproducible and sensitive. The developed method was successfully applied for the determination of N-acetyl-L-cysteine in pharmaceutical preparations.....

Keywords: Hybrid flow system, spectrophotometry, N-acetyl-L-cysteine

[1]. Aldini G, Altomare A, Baron G, Vistoli G, Carini M, Borsani L, Sergio F. N-Acetylcysteine as an antioxidant and disulphide breaking agent: the reasons why. 2018; Free Radical Research, 52: 751-762.
[2]. Amaral EP, Conceição, EL, Costa DL et al. N-acetyl-cysteine exhibits potent anti-mycobacterial activity in addition to its known anti-oxidative functions. 2016; BMC Microbiol 16, 251.
[3]. Samuni Y, Goldstein S, Dean OM, Berk M. The chemistry and biological activities of N-acetylcysteine. 2013; Biochimica et Biophysica Acta 1830 4117–4129.
[4]. Heard KJ. Acetylcysteine for Acetaminophen Poisoning. 2008; The New England Journal of Medicine, 359: 285-92.
[5]. Pei Y, Liu H, Yang Y, Yang Y, Jiao Y, Tay FR. Chen J, Biological Activities and Potential Oral Applications of N-Acetylcysteine: Progress and Prospects. 2018; Oxid Med Cell Longev. Volume 2018, Article ID 2835787, 14 pages

Abstract: The adsorption behavior of Methylene blue dye, Bismarck brown Y dye, and Indigo dye on to Sphagnum cymbifolium (moss) was investigated as a function of flow rate, and bed height through the fixed bed process. OBJECTIVES: One of the main objectives of this research is to expand the field of application of natural biomass for the treatment of dye waste waters from industrial effluents. Additionally, it is aimed at elucidating the dependency or otherwise of flow rate, and bed height using the fixed bed technique method of adsorption. METHODS: The biomass was characterized by Scanning Electron Microscopy (SEM) in order to examine the morphology of the biomass. The screened biomass samples were characterized at 1000 x magnification, and 500 x magnification respectively for their surface morphologies. This was done using a scanning electron microscope (FEI – Inspect/OXFORD INSTRUMENTS - X – MAX) which was equipped with an energy dispersive x-ray (EDAX) spectrophotometer employed for the elemental composition analyses. It was equally characterized with Fourier Transformed....

Keywords: Bio-sorption, Sphagnum cymbifolium, SEM, adsorbent, fixed bed

[1]. Kumar K., Savanesan, S., Ramanurhi, V. Adsorption of malachite green unto Pitophora sp. A fresh water algae / Equilibrium and kinetic modeling J of Process Bio Chem 2005; 2865 -2872
[2]. Panday, K., Prasad, G., Singh, V... Fly Ash-China Clay for the removal of Cr (VI) from aqueous solution. Indian J Chem1994; 51 – 52.
[3]. Crini G. Non-Conventional low cost adsorbents for dye removal. J of Bio Technol, 2006; 1061 – 1085.
[4]. Robinson T., Chundran, B. Nigam, P. Removal of dyes from a synthetic textile dye effluent by bio-sorption on apple pomance and wheat straw. J of Water Resources, 2002; 2824 – 2830.
[5]. Amadurai G., Janig, R.,Tee, D. Use of cellulose based waste for adsorption of dyes from aqueous solution. J of Hazardous Materials B, 2002; 263 – 274.
[6]. Chiou M., Hip, P. Adsorption of anionic dyes in acid solution using chemically cross-linked chitosan beads, J of Dye and Pigments, 2004; 69 –84.

Abstract: Imported acid activated bentonite clay is used in many solvent extraction (SX) plants of the Democratic Republic of Congo (DRC) to decontaminate the organic phase. This paper reports on test works carried out to evaluate whether clay sourced and activated locally could be used for the decontamination of oxime-based DRC SX plant organics. The sample of clay used was collected on the bank of Kalubwe River in Lubumbashi. The pre-treatment included: drying and screening (100 % passing 212 μm), activation in 10%, 20% and 30% sulfuric acid respectively during 30 min, 45 min and 60 minutes for each acid concentration, drying and further grinding. Organic performance parameters tested included Phase Disengagement Time, Extraction and Stripping Kinetics, copper selectivity over iron, and the loss of healthy oxime subsequent to the clay treatment process...

Keywords: Solvent extraction, phase disengagement time, extraction and stripping kinetics

[1]. Al-Zahrani, A.A., Al-Shabrani, S.S. and Al-Tawil, Y.A., 2000. Study on the activation of Saudi Natural Bentonite, Part 1. Internet acticle, King Abdulaziz University, Jeddah 21413, Saudi Arabia, April 2000.
[2]. BASF Mining and oilfields chemicals, 2011. Clay treatment presentation.
[3]. BASF Mining Solutions, 2013. Clay treatment training presentation.
[4]. Bishop, M.D. et al, 1999. Investigation of evaporative losses in solvent extraction circuits, Proceedings of the copper 99 International conference, Vol IV, Phoenix, AZ, USA, Oct 1999.
[5]. Cognis BASF, 2007. Operation of copper solvent extraction plants..

Abstract:A kinetic approach was used to study the oxidation of As(III) and reduction of Cr(VI) simultaneously in aqueous phase, and in the presence of DOM. Reactions were monitored by UV-visible spectrophotometry. The stoichiometry of the reaction was 1 : 3 (𝐶𝑟2𝑂72− 𝑡𝑜 𝐴𝑠𝑂2−). The reaction products were identified as Cr(III) and As(V). DOM was characterized by UV-visible Spectrophotometry, Fourier Transform Infrared Spectroscopy, FTIR and Scanning Electron Microscopy, SEM. The rate equation for the reaction is proposed as
–d[𝐶𝑟2𝑂72−]/dt = 𝑘2[𝐶𝑟2𝑂72−][𝐴𝑠𝑂2−]

Keywords: Arsenic(III), chromium(VI), kinetics, oxidation-reduction, dissolved organic matter

[1]. C. R. Ramakrishnaiah and B. Prathima, Hexavalent chromium removal from industrial watsewater by chemical precipitation method, International Journal of Engineering Research and Applications (IJERA), 2012, 2(2); 599-603.
[2]. J. H. Duffus, Heavy metals-a meaningless term? International Union of Pure and applied Chemistry, 2002, 74(5); 793–807.
[3]. A. Arruti, I. Fernández-Olmo and A. Irabien, Evaluation of the contribution of local sources to trace metals levels in urban PM2.5 and PM10 in the Cantabria region (Northern Spain), Journal of environmental monitoring, 2010, 12(7); 1451–1458.
[4]. G. Dönmez and Z. Aksu, Removal of chromium (VI) from saline wastewaters by Dunaliella species, Research Journal of Environmental Toxicology, 2002, 38(5); 751–762.
[5]. J. A. Wilkie, and J. G. Hering, Rapid oxidation of geothermal arsenic(III) in stream waters of the Eastern Sierra Nevada, Environmental science and technology, 1998, 32; 657–662.

Abstract: Late improvements concerning the utilization of polymer upheld organ metallic reagents in strong stage blend are assessed, with an uncommon spotlight on philosophy for carbon-carbon arrangement. Instances of responses that are covered incorporate the old style Suzuki, Sonogashira and Heck coupings, yet additionally aryl amination, epoxide opening, adjustments, metathesis and cyclopropanation. Applications in the field of unbalanced combination are likewise examined. Polymer upheld reagents have discovered numerous applications as of late. Researchers in exploration labs of agrochemical and drug ventures currently regularly use these mixtures to plan gatherings of little natural atoms for screening. This survey is intended to feature probably the main utilizations of these promising materials in natural blend. Moreover, a broad posting of polymeric reagents that were as of late utilized in natural blend is incorporated.

Keywords: polymer supported; organ metallic; solid phase synthesis; cross-coupling; metathesis; allylic substitution; transfer hydrogenation; aryl amination.

[1]. Ley, S.V.; Baxendale, I.R.; Bream, R.N.; Jackson, P.S.; Leach, A.G.; Longbottom, D.A.; Nesi, M.; Scott, J.S.; Storer, R.I.; Taylor, S.J. Multi-step organic synthesis using solid-supported reagents and scavengers: a new paradigm in chemical library generation. J. Chem. Soc. Perkin
[2]. Clapham, B.; Reger, T.S.; Janda, K.D. Polymer-supported catalysis in synthetic organic chemistry. Tetrahedron 2001
[3]. Bergbreiter, D.E. Using soluble polymers to recover catalysts and ligands. Chem. Rev. 2002, 102,
[4]. Leadbeater, N.E.; Marco, M. Preparation of polymer-supported ligands and metal complexes for use in catalysis. Chem. Rev. 2002.
[5]. McNamara, C.A.; Dixon, M.J.; Bradley, M. Recoverable catalysts and reagents using recyclable polystyrene-based supports. Chem. Rev. 2002..