The phytochemical screening and comparative study of antimicrobial activity of Aloe vera extracts was carried out. The phytochemical screening revealed the following metabolites: saponins, alkaloids, glycosides, tannins, protein, and flavonoids. While cardiac glyocosides and steroids were absent. The antimicrobial activities of the gel in 10% DMSO, methanol and aqueous extracts of green rind and leaf pulp were carried against some pathogenic clinical isolates, namely, Bacillus subtilis, Staphylococcus aureus, Proteus mirabilis and Candida albicans. The DMSO extract of the gel and the methanol extract of the green rind showed greater potency against tested microorganisms in the order B. Subtilis> S. aureus> C. albicans and S. aureus>C. albicans>B. subtilis>P. mirabilis respectively with different zones of inhibition ranging from 18 to 35 mm gel, 15 to 18 mm for leaf pulp methanol, 20 to 32 mm green rind methanol, also 12 to 14 mm and 14 to 23 mm for leaf pulp aqueous and green rind aqueous respectively. The minimum inhibitory concentration (MIC) of the extracts against organisms ranged from 6.25 to 25 mg/ml while the minimum bactericidal concentration (MBC) was within the range of 12.5 to 50 mg/ml. The study revealed that the green rind methanol extract and gel have greater medicinal potential against B. subtilis.

The human body uses oils and fats in the diet as an energy source, as a structural component and to make powerful biological regulators. The significance of trace metals and toxicological effects of heavy metals on human health and nutrition have been increasingly studied in recent years. Micronutrients play a role in cellular defences, acting both as 'sinks' for free radicals or by being involved in the activity of the enzymes required to deal with the oxidative products e.g. zinc and copper in superoxide dismutase. Presence of metals in edible oil could be from soil or during the manufacturing process. In this present study, the levels of some metals were determined in vegetable oils sold in Zaria, Nigeria. The concentration ranged from 19.

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Background: Atomic Absorption Spectrophotometer was applied to study the impact of human activities on the bed of River Benue, the second largest river in NigeriAtomic Absorption Spectroscopic (AAS) method is most commonly being used due to its reproducibility of results, short analysis time, cost effective, lower level detection and hyphenated in nature.a. Sediments were collected at four distinct stations designated ST1 – ST4 representing areas impacted by various contaminants to different degrees. The sediments are generally slightly alkaline with pH value ranging from 7.98 - 8.53. The concentrations (mg/kg) of 7 metallic elements of environmental implications which includes Cd, Pb, Cu, Fe Mn, and Zn were determined. Mean level of metal pollutants of toxicological concern Cd and Pb were 0.05 and 1.26 mg/kg. The decrease in concentrations of the metals across sampling stations followed this sequence Fe > Mn > Pb > Zn > Cu > Cd. Levels of all under studied metallic contaminant were significantly higher in samples from station S4 followed by S1 compared to S2 and S3 with lower degree of human activities. Levels of metals associated with the exchangeable, reducible, oxidisable and residual fractions ranged from 0.083 to 199.959; 0.037 to 219.118; 0.040 to 168.850 and 0.037 to 116.409 respectively. The mobility factor of cadmium in all the sample stations ranges from 28.06 – 69.27 mg/kg. The high value of Cd and Zn in the exchangeable fraction could indicate high mobility rate and readily availability of these metals for uptake by aquatic organisms. The aim of the study was therefore to assess the impact of metallic contaminants on the sediment, evaluate the pollution status of the sediments by the application of geoaccumulation index and their mobility rate. Aim: The concentrations in mg/kg of six heavy metals of environmental implications which includes Cd, Cu, Fe, Mn, Pb and Zn were determined by Atomic Absorption Spectrophotometer PG Instrument Model AA090M046. Methods: Soil and sediments samples were collected at four distinct stations, designated ST1-ST4 which represents areas impacted by human activities on the bank and bed of River Benue, the second largest river in Nigeria. The mean concentrations of Cd and Pb (0.05 mg/kg and 1.26 mg/kg) were of toxicological concern. The decrease in concentrations of the metals across sampling stations followed this sequence Fe > Mn > Pb > Zn > Cu > Cd. The concentration of all heavy metals studied were significantly high in samples from station S4 and S1 compared to S2 and S3. Levels of metals associated with the exchangeable, reducible, oxidisable and residual fractions ranged from 0.083 mg/kg to 199.959 mg/kg; 0.037 mg/kg to 219.118 mg/kg; 0.040 mg/kg to 168.850 mg/kg and 0.037 mg/kg to 116.409 mg/kg respectively. Results: The soil and sediments were slightly alkaline with pH values ranging from 7.98 - 8.53. The mobility factor of cadmium in all the sample stations ranges from 28.06 – 69.27 mg/kg. The high value of Cd and Zn in the exchangeable fraction could indicate high mobility rate and readily availability of these metals for uptake by aquatic organisms. Conclusion: The aim of the study was therefore to assess the impact of metallic contaminants on the sediment, evaluate the pollution status of the sediments by the application of geoaccumulation index and their mobility rate.

Sodium benzoate and potassium sorbate are chemical preservatives commonly used in fruit juice and soft drinks. In this study, a total of 20 commercial brands of such beverages in Nigeria were analysed for Sodium benzoate and Potassium sorbate using a UV-Vis spectrophotometric method. Preliminary validation of the method revealed good accuracy and precision; 94.54 -97.25% mean recovery was recorded for benzoate and 92.7 -96.82% for sorbate. % RSD for intraday precision was 1.67% and 2.36% for benzoate and sorbate respectively. The limits of detection and quantitation (LOD, LOQ) were 1.35, 0.87mg/L for sodium benzoate and 4.11, 2.56mg/L for potassium sorbate. The samples analysed all contained sodium benzoate in concentrations ranging from 25.80 to 245.10 while for potassium sorbate, fourteen samples tested positive with concentrations between 1.36 -158 mg/L. All the obtained concentrations for potassium sorbate were within acceptable limits but for sodium benzoate, seven samples were found with concentrations above permissible limits. Exposure estimation and health risk assessment carried out in this study revealed potential risks from the sodium benzoate content of some samples. The consumers that are prone to these risks are mainly children with body weights ≤ 30kg. Based on these findings, we recommend that the feeding of soft drinks and related beverages to children should generally be done with caution.