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Trace metals when present in crude oil or fuels are of economic significance in refining and to the combustion engines that use them. Herein, we develop a laboratory activity that trains students on how to analyze crude oil samples for ash and trace metal content while giving them the opportunity to acquire skills needed as a quality control analyst in the industry. Students were divided into three groups and were trained on sample preparation, standard preparation, and quantificational and operational use of the flame atomic absorption spectrophotometer. Each group after preparing their samples quantified the concentration of Pb, Cu, Ni, Zn, and Mn in crude oil samples. The discussion over the results enabled the students to draw inferences on the sampling methods, and ways to improve precision and accuracy in instrumental analysis.

Sabore field is characterised by a high level of artisan activities that contributes to water pollution by heavy metals; these heavy metals when present in drinking water can be deleterious to human health. Consequently, in 2018 we investigated the seasonal variations of the water samples from the Sabore vicinity to determine its suitability for drinking. Six metals (Mn, Cu, Cd, Zn, Ni, Pb) were studied, the health risk assessment was investigated using Hazard Index (HI), Hazard Quotient (HQ) and Cancer Risk (CR). The results showed that water from this locality have HI values > 1, Pb and Cd were top contributors to non-carcinogenic risk while Ni and Cd caused concern for carcinogenic health risk making it unsuitable for consumption. The seasonal spread of the metals shows that Mn varied from 148 to 976 µg/L; Cu from 923 to 1676 µg/L; Cd from 1.167 to 22.5 µg/L; Zn from 63 to 118 µg/L, Ni from 37 to 95 µg/L and Pb from 128 to 185 µg/L in the rainy season. For the dry season, Mn shows a spread of 1442–1802 µg/L; 344–776 µg/L for Cu; 57–82 µg/L for Cd; 48–187 µg/L for Zn; 147–242 µg/L for Ni and 79–256 µg/L for Pb. The increased concentration of some metals during the dry seasons could be attributed to the increased human activities around the field, increased evaporation rate, absence of rainfall and runoff water. The heavy metal content of water from some of the sites exceeded the stipulated permissible limits and poses serious health risk to its consumers. [ABSTRACT FROM AUTHOR]

Background: Cataract is a major cause of visual impairment and blindness around the world. This study evaluated the in vitro antioxidant and anti-cataract activities of Cnidoscolus aconitifolius leaves extract and fractions. Antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3- ethylbenzothiozoline-6-sulfonic acid) (ABTS), total reducing power, and hydrogen peroxide scavenging assays. Anti-cataract potential was evaluated in vitro using goat lenses divided into eight groups of different treatments and incubated in artificial aqueous humor at 37 °C for 72 hours. Glucose-induced opacity in the lenses was observed and biochemical indices quantified (catalase, Malondialdehyde (MDA) and total protein in the lens homogenate). Results: The crude extract and its fractions possess substantial antioxidant activities. The aqueous fraction exhibited the best DPPH radical scavenging activity (IC50 value 78.599 μg/ml); while the dichloromethane fraction exhibited the highest ABTS radical scavenging activity with IC50 66.68 μg/ml. The anti-cataract evaluation of crude and fractions at 250 μg/ml showed a significant increase (p<0.05) in the total protein and catalase activity compared to the cataract control group. The malonaldehyde level decreased significantly (p<0.05) in all the treated groups. Conclusion: These results suggest that Cnidoscolus aconitifolius leaves extract possesses protective actions against oxidative damage and cataract caused by oxidative stress. [ABSTRACT FROM AUTHOR]

Bioethanol is an environmentally friendly alternative to petroleum energy sources. This study evaluated the effects of HO, HCl, NaOH and FeCl pretreated rice husk feedstocks on the production of bioethanol. The pretreatments were carried out using water, 0.1 M HCl, NaOH and FeCl at 121 °C for 15 min, followed by simultaneous saccharification and fermentation (SSF) as well as separate hydrolysis and fermentation (SHF). The raw and pretreated lignocellulosic feedstocks were analyzed using Fourier transform infrared spectroscopy. Saccharification and fermentation were accomplished using Trichoderma reesei cellulase and Saccharomyces cerevisiae, respectively. The products obtained after saccharification and fermentation were collected and analyzed for reducing sugars and ethanol contents using 3,5-dinitrosalicylic acid and high-performance liquid chromatography, respectively. Enzyme hydrolysis of the FeCl and HCl treated samples resulted in hydrolysates containing 3.845 and 3.402 mg/ml glucose equivalent, respectively. In all pretreatments, SSF for each pretreatment produced more ethanol than the SHF method; the FeCl pretreatment gave the highest ethanol yield of 3.011 ± 0.034 and 3.802 ± 0.041% in the SHF and SSF methods, respectively. Utilization of FeCl pretreatment of rice husk is a potential option for bioethanol production in the future. [ABSTRACT FROM AUTHOR]

The use of Senecio aureus for therapeutic purposes is well known; however, in recent times, much concern has been raised regarding the toxicity of this plant extract used in treatment of gynecological disorders and jaundice. The sub-chronic oral toxicity of Senecio aureus was investigated. 16 male wistar rats were divided into four groups: control and treatments (100, 300 and 500 mg/kg body weight). Each group received the graded dose of the extract by gavage daily for 28 days while control received water. The administration of the extract resulted in significantly (p<0.05) increased total bilirubin and cholesterol and level from 29.14±1.18mg/dl and 83.00±7.16 mg/dl in the control to 53.19±6.11mg/dl and 166.67±14.03mg/dl, respectively, at dose of 500 mg/Kg body weight. In the hematological analysis, there were no significant changes compared to the control group (p<0.05). The present result suggests that the prolonged use of this plant extract at high dose in the treatment of diseases could be detrimental to the liver. [ABSTRACT FROM AUTHOR]