Statistical approach to optimization of the transesterification reaction from sorrel (hibiscus sabdariffa) oil

In an effort to optimize the reaction conditions of biodiesel production from Sorrel seed oil, Response Surface Methodology (RSM) was applied and the effects of reaction temperature, catalyst amount, reaction time and methanol/oil molar ratio, and their reciprocal interactions were ascertained. A total of 30 experimental runs were designed by Central Composite Rotatable Design (CCRD) and carried out. A quadratic polynomial was obtained for predicting the Transesterification process and the ANOVA test showed the model to be significant (p<0.05). The validity of the predicted model was confirmed by carrying out three independent replicates experiments. The actual maximum biodiesel yield obtained was 99.23% (w/w) at methanol/oil molar ratio 6.21, catalyst amount 1.03 (% wt.), reaction temperature 51 oC, and reaction time 63 min. The fuel properties of Hibiscus sabdariffa methylester (HSME) produced were found to be within the ASTM D6751 and DIN EN 14214 biodiesel standards. The fatty acid profile of the HSME revealed that the dominant fatty acids were oleic (58.34%), arachidic (1.55%), palmitic (18.28%) and linoleic (21.19%). Emission assessment revealed 70% reduction of CO at B80, 80% reduction of NO concentration at B40

HCME: An Environment-Friendly I.C. Engine Fuel

The study revealed that Hura crepitans oil is a good candidate for Hura crepitans methyl ester (HCME) production. Two steps (esterification and transesterification) production stages influenced the high yield of HCME. Three possible experimental runs were performed in each step, the best of the three conditions were 1.45 (% v/v) for H2SO4 conc., 5:1 for methanol/oil molar ratio, 40 min for reaction time which gave 1.06 % for FFA in the first step, in the second step, 92.70 %(w/w) of HCME was obtained at 0.55% KOH, 5:1 methanol/oil molar ratio, 60 oC temperature and 30 min reaction time. The produced HCME had fuel properties which satisfied both ASTME D6751 and EN 1424 standards. The fatty acid profile of the HCME revealed the dominant fatty acids were linoleic (64.50%), oleic (17.54%) and palmitic (12.70%). Exhaust emissions from an internal combustion (I.C.) engine revealed that there is 60% decreased in CO, 58% decreased in NOx, 60% decreased in HC, 39% decrease in smoke opacity and 42% decreased in BSFC at B20, respectively. Flue gas temperature increased by 12% at B20, 45% increased in BTE at B50 when compared to pure diesel (AGO). Hence, it can be concluded that B20 (20% HCME + 80% AGO) will provides the best emission reduction at the lowest cost

Geochemical Classification and Geotectonic Setting of Granitic Gneisses from Southeastern Margin of Western Nigeria Basement

Chemical whole-rock major oxides and some trace element analyses were done on granitic-gneiss rocks from Dagbala-Atte District, located on the southeastern margin of western Nigeria Basement Complex. This was meant to classify the rocks and to understand the tectonic setting in order to evaluate their crustal evolution. The chemical analyses were done using inductively-coupled plasma mass spectrometer. From the results obtained, these rocks classified into calc-alkaline to shoshonite series with metaluminous to peraluminous varieties. They are I-type granitoids of feroan composition. The granitic gneisses formed from metamorphism of granite and granodiorite. Tectonically, most of the rock samples plotted in the field of island arc, continental arc and continental-collisional granitoids,which indicated that the protolith granite and granodiorite are orogenic and are arc related inferring arc tectonic setting

Investigation of the antioxidant activity and quantification of the amount of heavy metals and some vitamins in carrot

Background: Carrot is a root vegetable from the Umbelliferae family. It is a biennial plant grown for their edible root. Carrots are a good source of carbohydrates and minerals like Calcium, Phosphorus, Iron and Magnesium and may contain toxic amounts of metals as a result of run off effects. It is also rich in carotene, niacin, riboflavin, thiamine and vitamin C.Objectives: To determine the amounts of toxic heavy metals, quantify the amounts of vitamins A and E and investigate the antioxidant activities of Carrot.Method: The research investigated the antioxidant properties of carrot on the basis of the radical scavenging activity on DPPH (1,1-diphenyl-2-picryl hydrazyl), heavy metal analysis were carried out using Flame Atomic Absorption Spectrophotometer while analysis of vitamins was done using HPLC (High Performance Liquid Chromatography).Result: The carrot sample analyzed contained considerable amount of some toxic metals of interest (Cr 0.024, 0.105ppm; Cu 15.76, 30.95ppm; Fe 66.94, 103.95ppm; Zn 16.57, 44.22ppm; Pb 0.018, 0.021ppm) in the leaves and root respectively. The samples also contain a very good amount of the vitamin A (12.863, 44.977ppm) and Vitamin E (0.087, 0.22ppm) in leaves and root respectively. It also showed some antioxidant activity and test positive for most phytochemicals.Conclusion: The actual concentrations of the respective heavy metals found in two parts of the D. carota samples were within the threshold limit but there was slight variation in the amount present in the root D. carota as compared to its leaf. The root had more concentrations of the metals and this could be due to the fact that the root is more exposed to these metals during plant uptake.Keywords: Heavy metals, Vitamin, DPPH, Antioxidant, Daucus carot

Factors Influencing Rental and Capital Values of Residential Investment Property in Abuja, Nigeria

There are various purposes the rental or capital values of residential investment property could be sought. However, most previous studies on factors influencing value of residential investment property are expressed in a general term; not specifically indicating whether rental or capital value. This may mislead investors in making the wrong investment decision. Using aggregation and disaggregation approach, this study examined the general and specific factors determining the rental and capital values of residential investment property in Abuja, Nigeria with a view to providing information that could guide the investment decisions. With the use of a structured questionnaire, cross sectional survey was adopted to obtain the perceptual opinion from 136 estate surveying and valuation firms in the study area. Data was analyzed with descriptive statistics of Relative Important Index (RII). The findings reveal a variation in the outcome of general factors and specific factors and that in specific term, factors influencing the capital value are significantly more in quantity and rating than the ones influencing the rental value. Out of the 23 (13 for rental and 10 for capital value) general determining factors, 11 (3 for rental and 8 for capital value) are actually significant. Average number of rooms; change in maintenance cost/taxes and the neighbourhood characteristics mainly influence the rental value of residential property while cost of construction; type of structure/quality of facilities; potential of rental growth; title and size of the land; neighbourhood attributes; inflation impact; size and structural characteristics and state of supply in property market are the main factors influencing the capital value. This noted variation is an indication for property investment stakeholders to be cautious and specific in the selection of the most appropriate determining factors for their investment objective to avoid investment decision errors

Phytochemical screening, antioxidant activity, antimicrobial activity and heavy metal quantification of Chrysophyllum albidum fruit extract (sapotaceae)

Background: Chrysophyllumalbidum (Sapotaceae) is a forest fruit tree described by the Scottish botanist George Don. It is commonly found throughout tropical Africa with the common name “white star apple”. Chrysophyllumalbidumis popularly called Agbalumo in the Southwestern region of Nigeria andclosely related to the African star apple (Chrysophyllumafricanum).Objectives: This study aims to determine the phytochemical constituents of the Chrysophyllumalbidum fruits, quantify its heavy metals composition and also determine the antioxidant and antimicrobial activity of the fruit.Material and Methods: Phytochemical screening of the fruit extract was carried out using standards methods while the antioxidant activity was done using DPPH (2, 2-Diphenyl-1-picrylhydrazyl). Atomic absorption spectrophotometer was used to detect and quantify the level of some toxic metal (Cadmium, Lead, Iron, Copper, Chromium, Zinc) contamination of the fruit. Antibacterial assay was carried out using disc diffusion method with measured zones of inhibition.Results: Results obtained reveal the presence of flavonoids, indicative of its antioxidant potentials, tannins and saponin. Heavy metals were also found to exist in varying amount in the fruit with the conspicuous absence of Cadmium. The antimicrobial assay showed increasing activities with increasing concentrations.Conclusion: The fruit of C. albidum, thus possesses antibacterial and antioxidant activities and are so beneficial for consumption. However stringent environmental control needs to be put in place to minimise the level of soil contamination with heavy metals through various human explorative activities.Keywords: Heavy metal, Antioxidant, Antimicrobial, Chrysophyllumalbidu

Factors Influencing Rental and Capital Values of Residential Investment Property in Abuja, Nigeria

There are various purposes the rental or capital values of residential investment property could be sought. However, most previous studies on factors influencing value of residential investment property are expressed in a general term; not specifically indicating whether rental or capital value. This may mislead investors in making the wrong investment decision. Using aggregation and disaggregation approach, this study examined the general and specific factors determining the rental and capital values of residential investment property in Abuja, Nigeria with a view to providing information that could guide the investment decisions. With the use of a structured questionnaire, cross sectional survey was adopted to obtain the perceptual opinion from 136 estate surveying and valuation firms in the study area. Data was analyzed with descriptive statistics of Relative Important Index (RII). The findings reveal a variation in the outcome of general factors and specific factors and that in specific term, factors influencing the capital value are significantly more in quantity and rating than the ones influencing the rental value. Out of the 23 (13 for rental and 10 for capital value) general determining factors, 11 (3 for rental and 8 for capital value) are actually significant. Average number of rooms; change in maintenance cost/taxes and the neighbourhood characteristics mainly influence the rental value of residential property while cost of construction; type of structure/quality of facilities; potential of rental growth; title and size of the land; neighbourhood attributes; inflation impact; size and structural characteristics and state of supply in property market are the main factors influencing the capital value. This noted variation is an indication for property investment stakeholders to be cautious and specific in the selection of the most appropriate determining factors for their investment objective to avoid investment decision errors

Analysis of some selected toxic metals in registered herbal products manufactured in Nigeria

The use of herbal medicine has been on the increase in many developing and industrialized countries and Nigerians in particular has been using herbal medicine for many centuries. The approval of these herbal remedies by regulatory bodies has further encouraged the use of herbal remedies. The safety of these herbal remedies is however poorly understood. This study investigated the concentration of arsenic, cadmium, lead and mercury in twenty registered ready to use herbal products. Twenty brands of herbal remedies were purchased randomly from the Pharmacy shops in Lagos, digested with aquaregia (3:1 HCl: HNO3) and were analysed using atomic absorption spectroscopy (Buck 205 Atomic Absorption Spectrophotometer). There was no detectable lead in any of the 20 herbal samples; however, all the samples contained a detectable amount of one or more of the other metals of interest. The Oral Component Limit (OCL) for arsenic, cadmium and mercury as stated by USP are 1.5, 0.5 and 1.5 μg/g, respectively. All the samples contained arsenic and mercury below the USP OCL, while sixtyfive percent contained cadmium out of which fifty-five percent were above USP OCL. The results obtained from this study suggest a significant risk to consumers’ health considering the toxicity of these heavy metals.Key words: Herbal remedies, toxic heavy metals, atomic absorption spectrophotometry

Evaluation of the concentration of toxic metals in cosmetic products in Nigeria

It has been shown that heavy metals toxicity to humans is as a result of long term or high level exposure to pollutants common in the environment including the air, water, food and numerous consumer products such as the cosmetics and toiletries. In this study, we assessed the levels of toxic metals in different cosmetic products sold at local shops in Lagos, Nigeria. The cosmetic items included thirty creams and twenty lipsticks and lip glosses. These items were purchased from various shops at different locations in Lagos. The cosmetics were analyzed for heavy metals (arsenic, cadmium, lead, mercury and nickel) after digestion with concentrated acids HNO3: H2SO4: HClO4 in ratio 2:2:1. The concentrations of the selected toxic heavy metals were determined in duplicate using a Buck 205 flame atomic absorption spectrophotometer. All the samples analyzed contained a detectable amount of all the metals of interest. The concentration of the heavy metals in the samples ranged from 0.006 to 0.207 ppm. It is obvious from the present study that the use of some cosmetic products exposes users to low concentrations of toxic heavy metals which could constitute potential health risk to users since it has been known that heavy metals can accumulate in the biological system over time and are known to induce skin problems or diseases such as cancer. Further research to better understand the sources of heavy metals in cosmetic products is recommended.Key words: Toxic heavy metals, cosmetics, atomic absorption spectrophotometer, environment

Nutritional Composition and Fatty Acids Profile of Ficus Exasperata Fruit and Fruit Oil

The proximate compositions, mineral elements contents and fatty acids profiles of fruit oil of Ficus exasperata were studied with a view to investigating its nutraceutical potentials. The proximate analysis showed that the fruit contain valuable nutrients; (g/100g) crude protein (11.38 ± 0.02), crude fibre (16.78 ± 0.04), ash (9.68 ± 0.01), crude fat (4.28 ± 0.00), moisture content (7.58 ± 0.01), and carbohydrate (67.48 ± 0.01). The results of mineral analysis (in mg/100g) revealed the presence of potassium (3262.28 ±6.87), calcium (1721.00 ± 4.04), iron (330.81 ± 8.32), titanium (28.00 ± 0.01), manganese (18.08 ± 0.18), copper (14.04 ± 1.51), chromium (0.08 ± 0.02) and nickel (0.37 ± 0.11). The fatty acids profile showed that the fruit oil contains higher proportion of unsaturated fatty acids, linoleic acid (54.54 %) and oleic acid (18.89 %). The major saturated fatty acids detected include stearic acid (9.10 %), and palmitic acid (7.32 %). Thus the fruit could be another dietary source of nutraceuticals. Keywords: Fatty acids, Ficus exasperata fruit, Mineral elements, Nutraceuticals, Proximate constituents