Applied Chemistry

Omeprazole is chemically 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl) methyl] sulfinyl ]-1H benzimidazole. It works by blocking acid production in the stomach. This medication is known as a proton pump inhibitor (PPI). It is used to treat acid-related stomach and throat (esophagus) problems and also used in the treatment of dyspepsia, peptic ulcer disease (PUD), Gastro esophageal reflux disease (GORD/GERD), and Laryngopharyngeal reflux (LPR) and Zollinger–Ellison syndrome. From the literature survey conducted there is no simple method reported for the determination of Omeprazole in capsule dosage form. Hence an attempt has been made to develop a HPLC method for the determination of Omeprazole is capsule dosage form and validate the developed method. The method was validated with respect to linearity, precision, system suitability, and specificity. The response was linear in concentration range of 9.6µg/ml to15.6µg/ml. The value of correlation coefficient found to be 0.9992. The R.S.D% value for repeatability precision studies was 0.8500. For system suitability it is essential for the assurance of the quality performance of chromatographic system so five injections of standard drug solution were given to the system. The %RSD value for system suitability was 0.1645.

Sediment and fish (nile Tilapia, Oreochromis niloticus) were collected from six sites of Lake Hawassa namely; Tikur Wuha, Amora Gedel, Dorie Bafana, Central part of the lake, the opposite side of Amora Gedel and Referral Hospital sites. Concentration of heavy metals was analyzed quantitatively using Flame Atomic Absorption Spectrophotometer and Chemometric methods. The maximum and minimum mean levels (mg/kg dry mass) in different lake sediment sites were Cu (51.38-17.64), Mn (348.51-140.63), Cd (12.8764-403), Pb (30.05-6.72), Ni (26.73-8.43 ), Zn (367.84-147.49), Cr (14.15-5.34), Co (27.19-9.59 ), Mg (3859.86-1872.43), Na (4913.72-2903.043), Ca (5526.74 - 3608.71), K (4229.69-2255.57) and that of fish muscle were Cu (13.833-5.666), Mn (11.972-9.722), Zn (21.110-12.055), Ca (574-482), Mg (512-437), Na (771-681), K (903-785). The result shows that the metal concentration in sediment samples is in order of Ca > Na > K > Mg > Zn > Mn > Cu > Pb > Co > Ni > Cr > Cd. The detectable metals in Tilapia fish muscle were in order of K > Na > Ca > Mg > Zn > Mn > Cu. In all the samples, concentrations of metals in sediment samples were higher than those of fish samples.

In this work we reported the status of one of Ethiopia’s Great Rift Valley Lakes; “The ever expanding Lake known as Beseka” in respect to water quality parameters. A composite sample was prepared by combining equal volumes of water samples taken from five Sampling sites. Five physical parameters (pH, DO, EC, T° and Turbidity) were determined for all samples at the spot of sampling while other physical parameters such as TSS and TDS were determined in the laboratory. AAS was used for the determination of heavy metals Pb, As, Cd, Cr, Fe, and Pb while spectrophotometer was used to determine water hardness, total chlorine, NO3-, PO43-, NH3, SO42 Alkali metals Na and K are determined by Flame Photometer. The findings indicated that the lake was found to be alkaline with pH above nine and brakish with TDS value of 2569.70 mg/L. The measured higher values of EC and turbidity resulted from higher values of TDS and TSS. Also these values are much higher than the acceptable values for surface water such as lakes. Similarly Pb, Cd, As, F- and total Cl are above the permissible values while other Physical and chemical parameter are within the acceptable limit of both WHO and FAO Guidelines for drinking and irrigation water.

In this study, physicochemical properties of Gilgel Gibe-I hydroelectric Dam water were investigated. Water samples were collected three times per day, from six sampling sites of the Dam. Physicochemical parameters including pH, dissolved oxygen (DO), electrical conductivity (EC), Temperature and Turbidity were determined in situ, whereas, other parameters such as alkalinity, total dissolved solids (TDS), total hardness (TH), total suspended solid (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), phosphate, nitrate, chloride, fluoride and heavy metals like Fe, Cu, Zn, Co and Cd were analyzed by FAAS in the laboratory. The finding of the study revealed that some physicochemical properties such as pH, EC, turbidity and nitrate of the studied water samples were exceeding WHO permissible limit for surface water and only Fe were investigated in the sample and within permissible limit domestic purposes. But, the remaining studied parameters are below the permissible range prescribed in WHO guideline for the surface water.

A spectrophotometric method for the analysis of phorate (organophosphorus insecticide) is described. The analysis is based on the oxidation of organophosphorus pesticide with slight excess of N-bromosuccinimide (NBS) and the unconsumed NBS was determined with rhodamine B on a spectrophotometer (Genesis IOS V1.200) at ?max. 553nm. Beer’s law was obeyed in the concentration range of 0.10 to 1.00ppm. The method was successfully applied for the determination of phorate in vegetable samples. The validity of the proposed method was assessed by comparing it with the high performance liquid chromatographic method (HPLC) through statistical analysis. There was no significant difference between the two methods. In the absence of sophisticated equipment like high performance liquid chromatograph and gas liquid chromatograph, the proposed method could be used for pesticide residues analysis.

Chemistry of natural product has contributed significantly towards the improvement of modern medicine. Custard apple (Annona squamosa ) is a nutritional rich fruit and is largely valued for its taste. It is known to have some active ingredients which kills lung, colon, breast and pancreatic cancer cells. Therefore, consumption of this fruit is known to have aided in anti-cancer activities. The investigation is carried out to find the chemical composition, phytochemical analysis and evaluation of crust, pulp and the seed of custard apple. The chemical characteristics such as pH, titratable acidity, total sugar and lipids are also verified. The results revealed that seed, pulp and crust contains adequate amount of vitamin C, citric acid, carbohydrate, protein etc. The phytochemical analysis revealed that custard apple contains tannins, flavonoids, cardiac glycosides and steroids. Standard GC analysis of seed oils contain certain types of essential oils which are mainly aiding in anti-inflammatory, anti-cancer and anti-microbial properties. The antioxidant activity is evaluated using DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay. The presence of anthocyanins may also offer anti-cancer, anti-inflammatory and anti-viral benefits of custard apple.

Tri-ethylene (TEG) is used to inhibit the formation of natural gas hydrates in long transportation pipelines that convey gas from remote gas field to processing units. The degradation of glycol leads to its decomposition and reduction of its pH making it more acidic thereby, increasing its tendency to cause corrosion and subsequent blockage of production and transportation facilities. The possible effect of water on tri-ethylene glycol was ascertained in terms of changes in viscosity, pH, density and efflux time as table 1to4.Thus, the resulting effect of water on glycols (TEG) is high at room temperature and low at frozen temperature as was observed in terms of pH, viscosity and efflux time of the mixture.

2, 2-dihydroxy biphenyl-thiourea-formaldehyde (2, 2-DHBTF) terpolymer resin was synthesized by an eco-friendly technique in dimethyl formamide medium. The resin was characterized by elemental analysis, UV-Visible, FTIR, 1H NMR, 13C-NMR and viscometric measurement. The surface morphology of the terpolymer resin was established by scanning Electron Microscopy. The number average molecular weight was determined by non-aqueous conductometric titration. One of the important applications of these types of polymer is their capability to act as chelating ion-exchanger. The chelation ion-exchange properties of the terpolymer showed a powerful adsorption towards specific metal ions like Fe3+, Cu2+, Ni2+, Co2+ and Zn2+ . A batch equilibrium method was adopted to study the selectivity of the metal ion uptake involving the measurement of the distribution of the given metal ion between the polymer sample and a solution containing the metal ion over a wide range of concentrations and pH of different electrolytes.

A Steady State Mass Balance method (SSMB) in all different forms was used to calculate the critical load of sulphur and nitrogen for soil. The present load of sulphur (161.1 Eq ha-1 yr-1), nitrogen (49.9 Eq ha-1 yr-1) and ammonium (176.8 Eq ha-1 yr-1) were calculated from wet and dry deposition from Agra region. The values of critical load of sulphur and nitrogen for soil with respect to wheat (Triticum vulgaris), maize (Zea mays), rye (Triticale), potato (Solanum tuberosum), lemon (Citrus argentifolium), anjan grass (Cenchrus ciliaris) and bajra (Pennisetum typhoides) were calculated.The values of actual acidity calculated were lower than the values assessed by the RAINS-Asia model of this area. It has been concluded that chloride also plays an important role in the acid deposition which changes the value of critical load significantly.

A carbon based (Graphene) working electrode containing enzyme alkaline phosphatase, cellulose acetate and Poly Vinyl Pyrolidone (PVP), Ferrocene, Horseradish peroxidise and aq. KOH was specially designed and fabricated. It is then combined with Ag/AgCl reference and a platinum electrode to form a three electrode based amperometric biosensor for the electrochemical detection of Enterobacter aerogenes as biological warfare agent (BWA) in the presence and absence of Fe3O4 nanoparticles. Fe3O4 nanoparticles were synthesized by sol-gel technique and were characterized by UV-visible, FTIR, TEM and XRD techniques. Change in current response and OCP values helps in the detection of BWA in presence and absence of Fe3O4 nanoparticles. Effects of temperature, stirring and Fe3O4 nanoparticles on the BWA have also been investigated.