ghanaopendata/ghanaian-research-english huggingface dataset:
Characterization of the harmattan dust aerosol in central Ghana

Saharan dust transport over central Ghana in West Africa has been studied and the physical characteristics of the aeolian dust determined. The effects of the aeolian haze on some physical processes have also been discussed. Atmospheric dust during the 1995/96 Harmattan period has been sampled at Kumasi (6°40’N, 1o 34’W), at a height of 15 m above ground level using a HIAC/ROYCO 5250A automatic optical airborne particle counter. The dust particle number concentration ranges from about 9 - 24 particles/cm3 of air while the mass concentration or dust load varies between 14 .μg/m3 and 56 μg/m3. The mean, median, and geometric mean diameters of the dust particles are 1.11μ.m, 0.66 μm, and 0.87 μm respectively. The mode of the distribution is estimated at 0.55 μm. It is also estimated that the particles sampled have a settling velocity of 0.1 mm/s and that they are capable of being transported over a horizontal distance of about 300 km under moderate wind conditions. The availability of fine clay and silt in the Sahara Desert, the north-east trade winds and the movement of the Inter-Tropical Convergence Zone are important factors governing the wind transported dust over the West African region between November and March.

Source: KNUST
Characterization, Spatial Variation and Risk Assessment of Heavy Metals and a Metalloid in Surface Soils in Obuasi, Ghana

Soil contamination with heavy metals and metalloids has become an increasingly important issue in recent years. Objectives. The present study examines possible contamination of the environment with metals from gold mining activities in Obuasi, Ghana. Methods. Soil samples were collected from commercial and residential areas and tailing dams in Obuasi in order to investigate the extent of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu), zinc (Zn), cobalt (Co), chromium (Cr), nickel (Ni) and arsenic (As) pollution, create thematic maps showing the extent of heavy metals pollution, identify the sources of pollution, and to assess risks to humans and the surrounding ecological system. Results. Mean concentrations of metals from the study were found in the order of As > Cu > Zn > Cr > Ni > Pb > Co > Hg > Cd. The results showed that all communities were severely polluted with As, and distribution maps highlighted two hot spots at the sulfite treatment plant and Pompura treatment plant tailings dams. Additionally, the levels of Pb, Cu and Zn were elevated around the city center where vehicular traffic is very dense. Principal component analysis indicated that mining activities may have significantly contributed to metal levels in Obuasi soils. The potential ecological risk (RI) indicated that soils in 41% of the communities pose very high risks to the surrounding ecological system, 50% pose considerable risk, and 9% pose a moderate risk. Arsenic and Hg contributed 73 and 15% of the RI, respectively. The average hazard quotient due to soil As exposure was 2.51 ± 1.23 and ingestion of soils in 95% of the communities in the study area could pose non-carcinogenic health risks to children. Moreover, the average cancer risk for children from the communities was 1.13 × 10-3. Based on the United States Environmental Protection Agency (USEPA) recommendation for cancer risk of 10-6 to 10-4, the cancer risk for children (> 10-3) was higher in 45% of the studied communities. Conclusions. The central part of the study area is polluted with Pb, Zn and Cu, and As pollution is severe in all of the studied communities. The RI from all study sites revealed very high risk to the ecological system, including mammals. There could be non-cancer and cancer risks to Obuasi residents due to ingestion of As-contaminated soils, and children are particularly vulnerable. Competing Interests. The author declares no competing financial interests

Source: KNUST
Chemical analysis of drinking water from some communities in the Brong Ahafo region

This study consisted of the determination of the trace metals and some physiochemical properties in drinking water samples from the Brong Ahafo region of the Republic of Ghana, where drinking water samples are not treated before it is consumed. The purpose was to ascertain the quality of water from these sources. Samples were taken from fifteen sampling points and analyzed for the following parameters Fe, Cu, Mn, Zn, Al, NO3 -, NO2 -, SO4 2- , PO4 2-, and F- using the procedure outline in the Palintest Photometer Method. The data showed the variation of the investigated parameters in samples as follows: pH 5.57-7.54, conductivity (EC) 35-1216 μs/cm, turbidity 3.25-72.50 NTU, PO4 2- 1 0.32-9.30 mg/L, F- 0.32-1.05 mg/L, NO3 - 0.09-0.99 mg/L, NO2 - 0.006-0.114 mg/L, SO4 2- 3.33-8.02 mg/L, Cu 1.19-2.75 mg/L Fe 0.05-0.85mg/L, Zn 0.04-0.15 mg/L, Mn 0.003-0.011 mg/L and Al 0.05-0.15 mg/L. The concentrations of most of the investigated parameters in the drinking water samples from Brong Ahafo region were within the permissible limits of the World Health Organization drinking water quality guidelines. There were no correlations between metal concentrations in the drinking water samples.

Source: KNUST
Chemical analysis of drinking water from some communities in the Brong Ahafo region

This study consisted of the determination of the trace metals and some physiochemical properties in drinking water samples from the Brong Ahafo region of the Republic of Ghana, where drinking water samples are not treated before it is consumed. The purpose was to ascertain the quality of water from these sources. Samples were taken from fifteen sampling points and analyzed for the following parameters Fe, Cu, Mn, Zn, Al, NO3 -, NO2 -, SO4 2, PO4 2-, and F- using the procedure outline in the palintest photometer method. The data showed the variation of the investigated parameters in samples as follows: pH 5.57-7.54, conductivity (EC) 35-1216 μs/cm, turbidity 3.25-72.50 NTU, PO4 2- 1 0.32-9.30 mg/L, F- 0.32-1.05 mg/L, NO3 - 0.09-0.99 mg/L, NO2 - 0.006-0.114 mg/L, SO4 2- 3.33-8.02 mg/L, Cu 1.19-2.75 mg/L Fe 0.05-0.85mg/L, Zn 0.04-0.15 mg/L, Mn 0.003-0.011 mg/L and Al 0.05-0.15 mg/L. The concentrations of most of the investigated parameters in the drinking water samples from Brong Ahafo region were within the permissible limits of the World Health Organization drinking water quality guidelines. There were no correlations between metal concentrations in the drinking water samples.

Source: KNUST
Chemical and biological characteristics of streams in the Owabi watershed

In this investigation, concentrations of physico-chemical and bacteriological qualities of water samples from the major streams within the Owabi watershed in Kumasi, Ghana, were measured at five different locations. The streams were moderately soft and neutral, having a mean pH range of 7.08 ± 0.2 to 7.88 ± 0.6. Total dissolved solids, total suspended solids, grease and oil, alkalinity, and the major ion levels varied significantly at each sampling site. Nutrient levels were however low and did not show any clear variation at sample locations. The bacteriological quality of the water was poor, rendering it unsafe for domestic purposes without treatment. The poor bacteriological quality was due to direct contamination by animal and human wastes. The streams have an appreciable self-purification capacity which is stressed by persistent pollution overloads caused by expanding human activities within the catchment. Cluster analysis performed on the data to determine pollution patterns between the streams depicts that River Owabi was less polluted, Rivers Akyeampomene and Sukobri were moderately polluted, while River Pumpunase was highly polluted.

Source: KNUST
Chemical and biological characteristics of streams in the Owabi watershed

In this investigation, concentrations of physico-chemical and bacteriological qualities of water samples from the major streams within the Owabi watershed in Kumasi, Ghana, were measured at five different locations. The streams were moderately soft and neutral, having a mean pH range of 7.08 ± 0.2 to 7.88 ± 0.6. Total dissolved solids, total suspended solids, grease and oil, alkalinity, and the major ion levels varied significantly at each sampling site. Nutrient levels were however low and did not show any clear variation at sample locations. The bacteriological quality of the water was poor, rendering it unsafe for domestic purposes without treatment. The poor bacteriological quality was due to direct contamination by animal and human wastes. The streams have an appreciable self-purification capacity which is stressed by persistent pollution overloads caused by expanding human activities within the

Source: KNUST
Chemical characteristics and health hazards of heavy metals in shallow groundwater: case study Anloga community, Volta Region, Ghana

Five water samples each were collected from six shallow wells which serve as source of drinking water at different locations within the Anloga community of the Volta Region in Ghana. Samples were analyzed for physicochemical characteristics, and human health risk associated with the consumption of heavy metals in the samples was also assessed. The results showed that pH, EC, water hardness, fluoride and sulfate levels were below the maximum permissible levels recommended by the WHO for drinking but chloride and nitrate levels in well A6 were above their respective WHO limits. Concentration of heavy metals showed Cd and Pd toxicities in some of the wells since their concentrations were higher than the WHO accepted limit for drinking water. Estimated non-carcinogenic health risks of the metals through ingestion were less than 1 in some of the wells, indicating small to no health hazard; however, high non-carcinogenic risk was recorded in well 2, 3 and 5 indicating a potential health hazard to the local residents. Health risk through dermal injection of the metals was found to be less than 1, indicating no health risk associated with water samples via dermal absorption. Cancer risk computed for Cd ranged from 1.82E−02 in well A5 to 9.09E−02 in well A1 and A6, indicating that consumption of water from these wells could result in an excess of 2–9 cancer cases per 100 people. The risk of developing cancer from Pb as a result of consuming water from wells A1, A2 and A5 was estimated to be 3.69E−06

Source: KNUST
Chemical Composition of Rainwater over a Mining Area in Ghana

A comprehensive study on the chemical composition of rainwater was carried out in Obuasi, a gold mining town in Ghana. Rainwater samples were analyzed for major ions (Ca2+,Mg2+, K+, Na+, NH4+, Cl-,NO3- and SO42-) and trace metals (Fe, Al, Zn, Pb, Cr, and Cd). The rainwater was typically acidic with a mean pH of 4.76±0.47, which ranged from 4.0 to 5.6. The low pH found in the water suggests that the concentration of the alkaline particles in the rainwater were not high enough to neutralize acidic species present. SO42" and Cl”were the main anions, while Ca2+ and K+ were the main cations. Concentrations of trace metals in this study were compared with those of other studies conducted at different sites in the world. The result of this study generally suggests that rainwater chemistry in the area is strongly influenced by local anthropogenic sources (mining). The pollutants in rainwater samples were mainly derived from mining activities. Concentrations of Pb in all the samples were above the WHO permissible limit of 0.01 mg/L for drinking water.

Source: KNUST
Chemical Constituents and Biological Activities of the Leaves of Clerodendrum Splendens G. Don Verbenaceae

Clerodendrum splendens is a common medicinal plant found mainly in the tropical and sub-tropical regions of the world that is used in traditional medicine for the treatment of various conditions including ulcers, scrofulous infections, wounds, burns and asthma. The pet ether, ethyl acetate and 70% ethanolic extracts which were obtained by Soxhlet extractions of 1.0 kg of powdered leaves of C. splendens were evaluated for their anti-bacterial and anti-inflammatory properties. The ethyl acetate extract showed the highest activity in both assays with the strongest antibacterial activity against Escherichia coli and the least activity against Pseudomonas aeruginosa. It again demonstrated the highest percentage of inhibition of oedema in the anti-inflammatory assay with a maximal percentage of inhibition of 66.09 ±13.13%. Fractionation of the ethyl acetate extract led to the isolation of the known flavone apigenin and the cyclohexylethanoid Cleroindicin F. The structures of these compounds were determined by spectroscopic methods including 1D and 2D NMR as well as comparison with published data. The activity of the extracts and the presence of apigenin and cleroindicin F in the ethyl acetate extract provide scientific support to the traditional use of the leaves of C. splendens for the treatment of infections, wounds and other inflammatory conditions.

Source: KNUST
Chemical Composition, Antioxidant, and Antimicrobial Activities of the Leaf and Fruit Essential Oils of the West African Plum, Vitex doniana

Vitex doniana (West African plum or black plum) is a plant with varying phytoconstituents and biological activities across different countries. In this study, essential oils extracted from the leaves and fruits of Vitex doniana cultivated in Ghana were investigated for their antimicrobial and antioxidant activities. -e antioxidant actions of the essential oils were determined using hydrogen peroxide (H2O2), phosphomolybdenum, thiobarbituric acid reactive substances (TBARS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. For both essential oils, the total antioxidant capacities ranged from 44 to 68 µg/g AAE, the IC50 values for H2O2 scavenging activity were between 87 and 242 µg/mL, whereas that for DPPH assay were between 322 and 599 µg/mL. -e IC50 for the TBARS assay for both essential oils also ranged from 247 to 414 µg/mL. -e antimicrobial activities of the essential oils were investigated using the broth dilution assay. -e minimum inhibition concentration for the essential oils ranged from 12.5 to 50 mg/mL. BioClm inhibitory activity was also evaluated for both essential oils, and the fruit essential oil showed a half-maximal inhibition of bioClm formation (BIC50) at 44.40±0.6 mg/mL, whereas the BIC50 value of the leaf essential oil was 109.1±0.9 mg/mL. -e fruit essential oil was superior to the leaf essential oil in inhibiting the secretion of pyoverdine. Molecular docking analyses suggested that methyl cinnamate, ethyl cinnamate, p-menth-4-en-3-one, trans-α-ionone, benzyl benzoate, isobutyl cinnamate, and folic acid likely interacted with LasR and algC proteins, and hence, contributed to the inhibition of bioClm formation and pyoverdine secretion. Essential oils from Vitex doniana could, therefore, be exploited as a natural source of radical scavenging and antimicrobial agents and could be useful in the pharmaceutical, food, and cosmetic industries.

Source: KNUST
The chemical constitution of seed fats from some selected plant families in Ghana

A total of ten seed fats from four plant families, namely sapindaceae, Sapotaceae. Olacaceae and Flacourtiacae have been analyzed for their acylglycerides’ composition. The component free fatty acids and their methylesters from each seed fat have boon separated quantitatively on thin layer chromatography (TV) and identified by their retention times relative to authentic standards. The infra red spectra of the separa-ed free fatty acids and their methylesters were also run and compared with those of authentic standards. Hydroxamic acid derivatives of the fatty acid methylesters have also been prepared and their melting points determined and compared with standards. Each glyceride fraction was digested with pancreatic lipase (enzymatic hydrolysis) to determine the relative positions of acyl groups in the glyceride. Putting the results obtained from all these analyses together, the most probable structures of the component acylglycorides in each seed fat have been proposed.

Source: KNUST
Chemical investigation of effluents from Chemistry Laboratories of some Senior High Schools in Kumasi, Ghana.

Many Senior High Schools in Ghana pursue science and science-related courses which require practical exercises. The Governments of Ghana have made conscious efforts to promote the study of science in senior high schools building of science laboratories and Science Resource Centres in selected senior high schools in the country. A variety of chemicals are used in the Chemistry Laboratories. With the increase in population of students who are pursuing chemistry and chemistry related courses, a lot of chemistry practical exercises are performed in the schools. The wastes generated during these practical exercises are disposed of into the sinks without any treatment. The effluents flow through the drains and eventually join water bodies. These water bodies may be used by people who live downstream for various domestic activities and for irrigation. In this study, laboratory effluents from five senior high schools in the Kumasi Metropolis were taken monthly from November 2010 to March 2011 for analyses. The objective of the study was to determine the quality of effluents from chemistry laboratories in selected Senior High Schools in the Kumasi Metropolis of Ghana and to assess whether the effluents could cause pollution using general effluent guidelines. The results were run using one way analysis of variance (ANOVA) and 95% confidence interval was set to determine the significant differences of the situations among the schools. The study revealed that most of the parameters measured were high above the recommended values by EPA Ghana for effluent from industries. There were no significant differences in most of the parameters among the schools. As the effluents flow downstream most of the parameters studied decreased in their levels. It was also found that the concentrations of phosphate were high in all the schools. This can cause eutrophication and harm aquatic life and thereby cause pollution of receiving water bodies.

Source: KNUST
Chemical Stability and a Novel Quinine Syrup Formulation for Pediatric Drug Use

Malaria is a public health problem worldwide, especially in tropical Africa where it kills around a million of people a year, of which 75% are children under 5 years of age, drug assessment in this group is lower which complicate the choice of appropriate treatment. Quinine is re-emerging as an important drug in the treatment of multiple-drug resistant or severe Plasmodium falciparum malaria. Chemical stabilities of brands of quinine syrup on the market were studied as well as the formulated product. Changes in percentage contents and pH were used as a tool for the study. UV-spectrophotometer was used for the analysis. This was done by preparing different concentrations of pure quinine sulphate in 0.1 M HCl solution and their respective absorbance determined at 250 nm. A calibration curve was plotted and the equation obtained was used for the quantification of quinine sulphate syrups bought from market. Two sets of each brand were analyzed. The analysis was done for a period of one week on each set. Brands A and D passed percentage content of 95 – 105 % on first sets of analysis, however, failed on the second sets. Brand A had a percentage breakdown of 3.76 and D 0.81% with pH changing within a range of 2.50 – 2.94. Brands B and E failed percentage content and had 13.97% and 1.34% percentage breakdown respectively with pH range of 4.78 – 5.69. Brand C also failed percentage content with percentage breakdown of 8.87% and having its pH changing within a range of 2.50 – 2.94. Quantitative solubility of quinine sulphate was established in citric acid, citrate buffer and in water using UV-spectrophotometer at 250 nm. Quinine sulphate had a solubility of iii 20.20 mg/ml in citric acid, 2.20 mg/ml in water and 12.67, 5.00, 0.0563, 0.153 and 0.188 mg/ml respectively in citrate buffer of pH 2, 3, 4, 5 and 6. Quinine sulphate syrup was eventually formulated. The formulation was done in a citrate buffer of pH 2 as the vehicle. This was necessitated by the outcome of the solubility test performed on the salt. The product had a pH of 2.30 with syrup strength of 40 mg of quinine sulphate per 5 ml. Anise water prepared from anise oil was effectively used to mask the taste. The product had a better stability when packaged in amber bottle than in plain bottle. The amber bottled product passed percentage content on the two sets of its analysis with virtually 0% breakdown and had a pH changing within 2.30 – 2.40. Plain bottled product on the other hand, failed percentage content and had a percentage breakdown of 12.73% with pH range of 2.30 – 2.60. Comparatively, the syrup strength of the formulated product of 40 mg/5ml (amber bottled product) stands at advantage over the market products of a reduced toxic effect in case of accidental overdose and again its high stability will also ensure accurate dosage delivery to avoid underdose. Key words: Quinine sulphate, Citric acid, Citrate buffer, UV-spectrophotometer, pH, solubility, chemical stability, plain and amber bottled products.

Source: KNUST
The chemistry of three indigenous seeds, and the extraction, nutritional and industrial potentials of their oils

This thesis describes the chemistry of the seeds of Carapa procera (Monkey cola), Pentadesma butvracea (Tallow tree) and Telfaira occidentalis (fluted pumpkin), the extraction, nutritional and industrial potentials of their seed oils. The oil content of the seeds ranged from 46.45% to 66.19% and protein, from 6.34% to 22.54%. Ash values ranged from 2.78% to 3.93% whilst seeds of P butyracea contained the highest fibre and carbohydrate values of 13.73% and 22.44% respectively. Chemical composition of defatted seeds showed protein values to be from 8.01% to 54.68%. Fibre contents ranged from 6.40% 15.22%. Ash and carbohydrate values ranged from 3.53% to 10.91% and from 24.69% to 64.56% respectively. Amino acid composition analysis revealed that the seeds were low in sulphur containing amino acids. The predominant fatty acids in all the seed oils were palmitic, stearic, oleic and linoleic acids. The iodine and saponification values ranges were 51.59% to 99.45% and 194.42% to 214.37% respectively. All the oils had low unsaponifiable matter and acid values. Optimization of aqueous extraction parameters showed that more than 50% of the oils were extractable. Both C. procera and. P. butvracea oils could be optimally extracted for 20 mins. using a meal : water ratio of 1:7 when the seeds were roasted at 100°C, for 30mm and at 120°C for 45mins respectively. With T..; occidentalis however, seed roasting at 100°C for 30mins, using a meal: water ratio of 1:6 and an extraction time of 30 mins. were required to achieve optimum extraction. Nutritionally, only P. byraoea oil was comparable to palm oil, however all the oils had a good potential for soap making.

Source: KNUST