The percentage yield of rotenone extracted from Tephrosia vogelii leaves and seeds was investigated. Ten samples of well ground leaves and seeds were each subjected to extraction in soxhlet extraction system using trichloromethane, ethanol and methanol solvents for 24 h at room temperature. The maximum absorption wavelength of rotenone was determined using Ultra violet-visible spectrophotometer. Different solvent extracts were quantified using high performance liquid chromatography instruments fitted with Ultra Violet detector and their yield expressed as percentage rotenone. Trichloromethane recorded the highest rotenone yield from both leaves (8.3 and seeds 2.7%) compared to the other two solvents. Ethanol was second with 5.9% in leaves and 1.9% in seeds while methanol had 4.8% in leaves and 1.6% in seeds. In general, the leaves extracts were found to have a higher rotenone percentage yield by an average factor of 3 compared to seeds. Rotenone can be commercially extracted from T. Vogelii using ethanol that is locally available to complement natural pyrethrum insecticide industry. Key words: Rotenone, Tephrosia vogelii, solvents, seeds, leaves.
{"title":"Spectrophotmetric evaluation of rotenone extraction from leaves and seeds of mature Tephrosia vogelii plant","authors":"D. Kariuki, S. Njiru","doi":"10.5897/AJPAC2018.0760","DOIUrl":"https://doi.org/10.5897/AJPAC2018.0760","url":null,"abstract":"The percentage yield of rotenone extracted from Tephrosia vogelii leaves and seeds was investigated. Ten samples of well ground leaves and seeds were each subjected to extraction in soxhlet extraction system using trichloromethane, ethanol and methanol solvents for 24 h at room temperature. The maximum absorption wavelength of rotenone was determined using Ultra violet-visible spectrophotometer. Different solvent extracts were quantified using high performance liquid chromatography instruments fitted with Ultra Violet detector and their yield expressed as percentage rotenone. Trichloromethane recorded the highest rotenone yield from both leaves (8.3 and seeds 2.7%) compared to the other two solvents. Ethanol was second with 5.9% in leaves and 1.9% in seeds while methanol had 4.8% in leaves and 1.6% in seeds. In general, the leaves extracts were found to have a higher rotenone percentage yield by an average factor of 3 compared to seeds. Rotenone can be commercially extracted from T. Vogelii using ethanol that is locally available to complement natural pyrethrum insecticide industry. \u0000 \u0000 Key words: Rotenone, Tephrosia vogelii, solvents, seeds, leaves.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73137350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Schistosomiasis is a widespread parasitic infection globally but more so in sub-Saharan Africa which accounts for about 90% of those seeking treatment globally. Fresh water aquatic snails are intermediate hosts of parasites causing the disease. Niclosamide was approved by the World Health Organization to be the main molluscicide used in the control of the snails. However, many plant species could be used as alternative molluscicides as they are environmentally friendly. This study aimed to isolate and characterize the chemicals responsible for the molluscicidal activity in the plants, Phytolacca octandra, Phytolocca dodecandra and Balanites aegyptiaca. Parts of the whole plant (berries, leaves, stems and roots) were collected, air dried to constant weight, macerated to a fine powder and extracted separately using methanol in soxhlet apparatus. After extraction, the crude extracts were isolated and purified. The melting points of the isolated compounds were determined and testing was done for alkaloids, triterpenoids, glycosides and saponins. The tests were positive for triterpenoids, glycosides and saponins but negative for alkaloids. Key words: Schistosomiasis, molluscicide, Phytolacca octandra, Phytolocca dodecandra, Balanites aegyptiaca.
{"title":"Isolation and characterisation of chemical compounds from the plants, Phytolacca octandra (L.), Phytolacca dodecandra (LHerit) and Balanites aegyptiaca (L.) commonly used to control schistosomiasis transmitting snails in Kenya","authors":"S. Kariuki, J. Kariuki, B. M. Mailu, D. Muchiri","doi":"10.5897/AJPAC2018.0749","DOIUrl":"https://doi.org/10.5897/AJPAC2018.0749","url":null,"abstract":"Schistosomiasis is a widespread parasitic infection globally but more so in sub-Saharan Africa which accounts for about 90% of those seeking treatment globally. Fresh water aquatic snails are intermediate hosts of parasites causing the disease. Niclosamide was approved by the World Health Organization to be the main molluscicide used in the control of the snails. However, many plant species could be used as alternative molluscicides as they are environmentally friendly. This study aimed to isolate and characterize the chemicals responsible for the molluscicidal activity in the plants, Phytolacca octandra, Phytolocca dodecandra and Balanites aegyptiaca. Parts of the whole plant (berries, leaves, stems and roots) were collected, air dried to constant weight, macerated to a fine powder and extracted separately using methanol in soxhlet apparatus. After extraction, the crude extracts were isolated and purified. The melting points of the isolated compounds were determined and testing was done for alkaloids, triterpenoids, glycosides and saponins. The tests were positive for triterpenoids, glycosides and saponins but negative for alkaloids. \u0000 \u0000 \u0000 \u0000 Key words: Schistosomiasis, molluscicide, Phytolacca octandra, Phytolocca dodecandra, Balanites aegyptiaca.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80040458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metakaolin clay-derived geopolymer for recycling of waste cathode ray tube glass","authors":"B. Mary, S. Ikpeni","doi":"10.5897/ajpac2018.0759","DOIUrl":"https://doi.org/10.5897/ajpac2018.0759","url":null,"abstract":"","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76464170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Extraction, purification and nuclear magnetic resonance (NMR) assignment of garcinoic acid from Garcinia kola (bitter kola) fruit","authors":"J. B., H. J., Ortin Yannick, Evans Paul","doi":"10.5897/ajpac2018.0752","DOIUrl":"https://doi.org/10.5897/ajpac2018.0752","url":null,"abstract":"","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"142 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73974968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Beckley Victorine Namondo, J. Foba-Tendo, Ekane Peter Etape, R. Krause
The oil and raffia palm species are indigenous to West and Central Africa, and their exploitation both at industrial and artisanal scale generate important quantities of renewable fibrous biomass that can be converted to high and low value bio-based products. Fibre samples were prepared from three raffia palm species drawn from three locations and Oil Palm Empty Fruit Bunch (OPEFB) from an industrial palm oil mill, all in the South West Region of Cameroon. The samples were tested for chemical composition using wet chemical methods and an elemental analyzer. The functional groups were determined by Fourier Transform Infrared Spectrometer (FT-IR) spectroscopy while morphological analysis and crystallinity were evaluated by scanning electron microscopy and powder X-ray diffraction respectively. The results obtained show that extractives-free raffia palm fibres are similar to OPEFB with respect to lignin, hemicellulose and cellulose contents, morphology, occurrence of silica bodies on the surface of fibres and internal porosity. Scanning Electron Microscopy (SEM) indicated that the diameter of raffia fibre were larger than those of OPEFB stalk and spikelet fibres. The content of extractives determined by gravimetric method showed significantly lower values for raffia biomass compared to EFB fibres. The response of the fibres to hypochlorite treatment as revealed by FT-IR and morphological studies was very similar. The raffia fibres reflected significantly lower ash content and the powder X-ray studies showed slight differences in crystallinity index between raffia and OPEFB. The variability in key characteristics of biomass from the different species of palm are within the limits of the variability shown by biomass from the same species of plants. This leads to the conclusion that, the two types of palm which are both indigenous to the West and Central Africa can serve as source of blended renewable biomass. Promotion of cultivation and conservation of existing raffia plantations presents as a strategy for a more sustainable supply of biomass feedstock for bio-based products. Key words: Raffia palm, oil palm, fiber sample, Fourier Transform Infrared Spectrometer (FT-IR), Scanning Electron Microscopy (SEM).
{"title":"Potential of blended biomass feedstock from some species of raffia palm (Raffia farinifera, Raffia hookeri and Raffia vinifera) and Oil Palm Empty Fruit Bunch (OPEFB) from Cameroon","authors":"Beckley Victorine Namondo, J. Foba-Tendo, Ekane Peter Etape, R. Krause","doi":"10.5897/AJPAC2018.0753","DOIUrl":"https://doi.org/10.5897/AJPAC2018.0753","url":null,"abstract":"The oil and raffia palm species are indigenous to West and Central Africa, and their exploitation both at industrial and artisanal scale generate important quantities of renewable fibrous biomass that can be converted to high and low value bio-based products. Fibre samples were prepared from three raffia palm species drawn from three locations and Oil Palm Empty Fruit Bunch (OPEFB) from an industrial palm oil mill, all in the South West Region of Cameroon. The samples were tested for chemical composition using wet chemical methods and an elemental analyzer. The functional groups were determined by Fourier Transform Infrared Spectrometer (FT-IR) spectroscopy while morphological analysis and crystallinity were evaluated by scanning electron microscopy and powder X-ray diffraction respectively. The results obtained show that extractives-free raffia palm fibres are similar to OPEFB with respect to lignin, hemicellulose and cellulose contents, morphology, occurrence of silica bodies on the surface of fibres and internal porosity. Scanning Electron Microscopy (SEM) indicated that the diameter of raffia fibre were larger than those of OPEFB stalk and spikelet fibres. The content of extractives determined by gravimetric method showed significantly lower values for raffia biomass compared to EFB fibres. The response of the fibres to hypochlorite treatment as revealed by FT-IR and morphological studies was very similar. The raffia fibres reflected significantly lower ash content and the powder X-ray studies showed slight differences in crystallinity index between raffia and OPEFB. The variability in key characteristics of biomass from the different species of palm are within the limits of the variability shown by biomass from the same species of plants. This leads to the conclusion that, the two types of palm which are both indigenous to the West and Central Africa can serve as source of blended renewable biomass. Promotion of cultivation and conservation of existing raffia plantations presents as a strategy for a more sustainable supply of biomass feedstock for bio-based products. \u0000 \u0000 Key words: Raffia palm, oil palm, fiber sample, Fourier Transform Infrared Spectrometer (FT-IR), Scanning Electron Microscopy (SEM).","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"13 1","pages":"25-33"},"PeriodicalIF":0.0,"publicationDate":"2018-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89281696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study was conducted to assess the presence of pesticides residues in wheat from Misha woreda, Haiya Zone, Ethiopia. Samples of wheat were collected during the period December 2015 to August 2016. Gas chromatograph (GC-MS) detection was employed after Liquid-Liquid extraction (LLE). The concentration levels of eight pesticides have been investigated in both wheat samples in farm and purchased from storage facilities. Since the method was out of scope, it was validated before application to the analysis of these pesticides. The spiked recovery results for five analytes were within the acceptable international standard. The LOD value and LOQ value are below the LCC and MRL of the analyte. Method validation for this study maintained a RSD aldrin>p,p-DDT >Endosulfan. The study observed that from the detected analytes, none of them are above the international MRL values and suggested that stringent monitoring of use of pesticides in agriculture and food storage is required. Key words: Pesticide residue, wheat, Gas chromatography–mass spectrometry (GC-MS), method validation, maximum residue limit.
{"title":"Multi residue analysis of pesticides in pre and postharvest wheat grains in Misha Woreda, Hadiya Zone, Ethiopia","authors":"Demis Zelelew, Hadush Gebrehiwot, Dereje Bezuyehu","doi":"10.5897/ajpac2018.0751","DOIUrl":"https://doi.org/10.5897/ajpac2018.0751","url":null,"abstract":"This study was conducted to assess the presence of pesticides residues in wheat from Misha woreda, Haiya Zone, Ethiopia. Samples of wheat were collected during the period December 2015 to August 2016. Gas chromatograph (GC-MS) detection was employed after Liquid-Liquid extraction (LLE). The concentration levels of eight pesticides have been investigated in both wheat samples in farm and purchased from storage facilities. Since the method was out of scope, it was validated before application to the analysis of these pesticides. The spiked recovery results for five analytes were within the acceptable international standard. The LOD value and LOQ value are below the LCC and MRL of the analyte. Method validation for this study maintained a RSD aldrin>p,p-DDT >Endosulfan. The study observed that from the detected analytes, none of them are above the international MRL values and suggested that stringent monitoring of use of pesticides in agriculture and food storage is required. \u0000 \u0000 Key words: Pesticide residue, wheat, Gas chromatography–mass spectrometry (GC-MS), method validation, maximum residue limit.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"35 1","pages":"14-24"},"PeriodicalIF":0.0,"publicationDate":"2018-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76834859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Metal contamination in water is a major determinant of water quality. People who consume this water suffer from water borne diseases. There are various natural and anthropological activities at the sample collection site leading to increase in concentration of trace elements in drinking water. Activities like corrosion of metal coated pipes, herbicides, insecticides, ceramic wastes, taking gravel from near water source, etc. may lead to pollution of drinking water by heavy metals like chromium. The objective of this study was to detect metal concentration in spring and tap water from selected residential areas in the Gurage Zone. Tap water samples were collected from seven different locations during the rainy season. Samples were analyzed using atomic absorption spectrometry to determine the concentration of dissolved metal. Metal analysis was done to detect chromium, copper, zinc, lead, cadmium, magnesium and calcium. The results obtained were compared with guidelines for drinking water quality such as the World Health Organization (WHO) guidelines. Key words: Cadmium, copper, lead metal concentration, chromium, Gurage Zone.
{"title":"Analysis of physico-chemical properties and heavy metals content of drinking water from selected areas in Gurage Zone, Ethiopia","authors":"Sage Desalegn, Lera Israel, Kebede Wouduma","doi":"10.5897/AJPAC2017.0729","DOIUrl":"https://doi.org/10.5897/AJPAC2017.0729","url":null,"abstract":"Metal contamination in water is a major determinant of water quality. People who consume this water suffer from water borne diseases. There are various natural and anthropological activities at the sample collection site leading to increase in concentration of trace elements in drinking water. Activities like corrosion of metal coated pipes, herbicides, insecticides, ceramic wastes, taking gravel from near water source, etc. may lead to pollution of drinking water by heavy metals like chromium. The objective of this study was to detect metal concentration in spring and tap water from selected residential areas in the Gurage Zone. Tap water samples were collected from seven different locations during the rainy season. Samples were analyzed using atomic absorption spectrometry to determine the concentration of dissolved metal. Metal analysis was done to detect chromium, copper, zinc, lead, cadmium, magnesium and calcium. The results obtained were compared with guidelines for drinking water quality such as the World Health Organization (WHO) guidelines. \u0000 \u0000 Key words: Cadmium, copper, lead metal concentration, chromium, Gurage Zone.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"59 1","pages":"9-13"},"PeriodicalIF":0.0,"publicationDate":"2018-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84290795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interest in plants’ essential oils has grown recently due to increased use of natural products in medicine and cosmetics. In spite of its long use, there has been little prior study on the bioactivity and toxicity of the essential oils of Crassocephalum crepidioides (Benth S. More). Thus in this work, the anti-bacterial and brine shrimps’ lethality of the essential oils obtained through hydro-distillation were evaluated. The oils were analyzed by gas chromatography and gas chromatography/mass spectrometric techniques. The toxicity of the oils was considered using the brine shrimps’ lethality assay at concentrations of 10, 100 and 1000 ppm. The antimicrobial assay was carried out using the agar diffusion method. The bacteria were three strains of Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Salmonella Typhi) and two strains of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The main constituents of the leaves essential oil of C. crepidioides were α-caryophyllene (10.29%) and β-cubebene (13.77%), while the stem essential oil were mainly thymol (43.93%) and 4-cyclohexybutyramide (20.94%). The results of the brine shrimps’ lethality assay suggest that the essential oil of the stem (LC50 = 9.10 µg/mL) was just as toxic as the essential oil of the leaves (LC50 = 9.2 µg/mL). The essential oils were active against all the bacterial strains but low when compared with the standard antibiotic, Gentamicin. Key words: Essential oils, toxicity, antibacterial activity, Crassocephalum crepidioides, Nigeria.
{"title":"Anti-bacterial and brine shrimps lethality studies of the essential oils of Crassocephalum crepidioides (Benth S. More) grown in south west Nigeria","authors":"I. Owokotomo, E. P. Owokotomo","doi":"10.5897/AJPAC2017.0730","DOIUrl":"https://doi.org/10.5897/AJPAC2017.0730","url":null,"abstract":"Interest in plants’ essential oils has grown recently due to increased use of natural products in medicine and cosmetics. In spite of its long use, there has been little prior study on the bioactivity and toxicity of the essential oils of Crassocephalum crepidioides (Benth S. More). Thus in this work, the anti-bacterial and brine shrimps’ lethality of the essential oils obtained through hydro-distillation were evaluated. The oils were analyzed by gas chromatography and gas chromatography/mass spectrometric techniques. The toxicity of the oils was considered using the brine shrimps’ lethality assay at concentrations of 10, 100 and 1000 ppm. The antimicrobial assay was carried out using the agar diffusion method. The bacteria were three strains of Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Salmonella Typhi) and two strains of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The main constituents of the leaves essential oil of C. crepidioides were α-caryophyllene (10.29%) and β-cubebene (13.77%), while the stem essential oil were mainly thymol (43.93%) and 4-cyclohexybutyramide (20.94%). The results of the brine shrimps’ lethality assay suggest that the essential oil of the stem (LC50 = 9.10 µg/mL) was just as toxic as the essential oil of the leaves (LC50 = 9.2 µg/mL). The essential oils were active against all the bacterial strains but low when compared with the standard antibiotic, Gentamicin. \u0000 \u0000 \u0000 \u0000 Key words: Essential oils, toxicity, antibacterial activity, Crassocephalum crepidioides, Nigeria.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"24 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90923741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adolf Oti-Boakye, Akwasi Acheampong, Ohene Gyang Nathan, Akorfa Akosua Agbosu, Amoah Charles Agyei
The numerous reputed health benefits of the omega-3s (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]), particularly, their cardio-protective effects have led to the manufacture of omega-3 supplements by various pharmaceutical companies resulting in their flooding of the Ghanaian market. Coldwater fishes which are the primary sources of the omega-3 fatty acids are known to have high levels of mercury and cadmium in them. There is therefore the potential of mercury and cadmium poisoning in the course of people taking the omega-3 food supplements. Mercury and cadmium levels in ten products of omega-3 food supplements have been determined in order to ascertain their safety for human consumption. All the levels of mercury and cadmium determined were within the acceptable limits stipulated by Food and Agriculture Organization and World Health Organization, and therefore do not pose any health threat to consumers. Key words: Metals, omega-3, cardio-protective, pharmaceutical.
{"title":"Determination of mercury and cadmium levels in omega-3 food supplements available on the Ghanaian market","authors":"Adolf Oti-Boakye, Akwasi Acheampong, Ohene Gyang Nathan, Akorfa Akosua Agbosu, Amoah Charles Agyei","doi":"10.5897/AJPAC2016.","DOIUrl":"https://doi.org/10.5897/AJPAC2016.","url":null,"abstract":"The numerous reputed health benefits of the omega-3s (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]), particularly, their cardio-protective effects have led to the manufacture of omega-3 supplements by various pharmaceutical companies resulting in their flooding of the Ghanaian market. Coldwater fishes which are the primary sources of the omega-3 fatty acids are known to have high levels of mercury and cadmium in them. There is therefore the potential of mercury and cadmium poisoning in the course of people taking the omega-3 food supplements. Mercury and cadmium levels in ten products of omega-3 food supplements have been determined in order to ascertain their safety for human consumption. All the levels of mercury and cadmium determined were within the acceptable limits stipulated by Food and Agriculture Organization and World Health Organization, and therefore do not pose any health threat to consumers. \u0000 \u0000 \u0000 \u0000 Key words: Metals, omega-3, cardio-protective, pharmaceutical.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"436 1","pages":"50-53"},"PeriodicalIF":0.0,"publicationDate":"2017-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76665913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sulfur, selenium and tellurium-based metal chalcogenide films have been prepared using various deposition methods. Investigation of morphological properties of the generated surface structures on chalcogenide thin films using atomic force microscopy technique was reported. The purpose of this work is to describe past important research findings that are related to atomic force microscopy technique. Key words: Atomic force microscopy, surface roughness, film thickness, grain size.
{"title":"Atomic force microscopy studies on sulfur-, selenium- and tellurium-based metal chalcogenide thin films: A review","authors":"H. Soonmin","doi":"10.5897/AJPAC2017.0739","DOIUrl":"https://doi.org/10.5897/AJPAC2017.0739","url":null,"abstract":"Sulfur, selenium and tellurium-based metal chalcogenide films have been prepared using various deposition methods. Investigation of morphological properties of the generated surface structures on chalcogenide thin films using atomic force microscopy technique was reported. The purpose of this work is to describe past important research findings that are related to atomic force microscopy technique. \u0000 \u0000 \u0000 \u0000 Key words: Atomic force microscopy, surface roughness, film thickness, grain size.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"104 1","pages":"42-49"},"PeriodicalIF":0.0,"publicationDate":"2017-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89015327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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