Open Access Original Research Article

Effect of Harvest Time on Phytochemical Profile of Citrus aurantifolia Leaf Essential Oil Grown in North Central, Nigeria

T. C. Ogunyemi, C. M. Ekuma, T. O. Akintoye, S. T. Ogunyemi

International Research Journal of Pure and Applied Chemistry, Page 1-8
DOI: 10.9734/irjpac/2019/v19i430119

Citrus aurantifolia essential oils are volatile phytochemicals obtained from various part of the plant which has found wide range of domestic, medicinal and industrial applications. The research seeks to investigate the effect of time of harvest on the yield and phytochemical composition of Citrus aurantifolia leaf oil. Pulverized leaves of Citrus aurantifolia harvested in the morning (7a.m) and afternoon (2p.m) on the same day were separately subjected to hydro-distillation which yielded 0.4 and 0.5% (v/w) of the volatile oil respectively. Analyses of the oil harvested in the morning (7am) revealed the predominance of oxygenated terpenes which constituted 58.3%  of the oil. The principal constituents were; isolimonene (22.2%), neral (22.2%), citral (21.5%), caryophyllene (4.3%), and α-geranyl acetate (4.1%). Furthermore, the leaf oil from the afternoon (2pm) harvest also showed predominance of oxygenated terpenes which constituted 57.7%. The principal constituents in the oil were; limonene (20.2%), neral (24.5%), citral (10.3%), caryophyllene (5.4%), and α-geranyl acetate (3.3%). This study established   that there was compositional variation in the leaf essential oil obtained from the different time of harvests.       

Open Access Original Research Article

Assessment of Pesticide Residues in Fresh Vegetables from Three Major Markets in Lagos Using QuEChERS Method and GC-MS

O. Okediran, M. S. Dauda, S. A. Kolawole

International Research Journal of Pure and Applied Chemistry, Page 1-8
DOI: 10.9734/irjpac/2019/v19i430120

The study evaluates pesticide residues in fresh vegetables from three major markets in Lagos and verified compliance of these fresh vegetables with the maximum residue levels (MRLs) as specified by Codex Alimentarius Commission. The residues were extracted by means of multi residue method based on the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method, Gas Chromatography - Mass Spectrometry (GC-MS) was used to determine two organophosphates (dichlorvos and chlorpyrifos), two organochlorines (endosulfanII and chlorothalonil), two carbamates (carbaryl and carbofuran) and two pyrethroids(alpha-cypermethrin and lambda-cyhalothrin). Fifteen samples of five common vegetables (cabbage, lettuce, fluted pumpkin, bitter leaf and African spinach) were analyzed. The linear ranged used were 0.005, 0.1, 0.25, 0.5 and 1.0mg/l, resulting to r2 of ≥0.996. While the mean recoveries obtained for two fortification levels (0.1 and 0.25 ppm) in three replicates for lettuce control sample and spinach control sample were 96.7 to 104.3%, 96.3 to 101.3%, and 92.0 to 114.3% ,92.1 to102.1% respectively. A satisfactory precision of RSD<20% was recorded. The limit of detection (LOD) and limit of Quantitation (LOQ) were between 0.005 -0.050 mg/kg and 0.015-0.150 mg/kg respectively. Pesticide residues detected ranges from 0.025-0.529 mg/kg. EndosulfanII, Chlorothalonil, carbaryl and Carbofuran were not detected during the entire study. However, pesticide residues detected were below the MRLs specified by Codex Alimentarius Commission.

Open Access Original Research Article

Assessment of Heavy Metals Content in African Giant Rat (Cricetomys gambianus)

T. A. Atanda, O. O. Murana, O. J. Tijani, V. A. Adeyemi

International Research Journal of Pure and Applied Chemistry, Page 1-8
DOI: 10.9734/irjpac/2019/v19i430121

This study was undertaken to evaluate the concentrations of heavy metals in the liver, kidney and tissue of Africa giant rat (Cricetomys gambianus) in three (3) processing centers in Abeokuta, Ogun State, Nigeria with a view to determine its safeness for consumption. Atomic Absorption Spectroscopy was used to determine the concentrations of heavy metals in the liver, tissue and kidney of Africa giant rat. Data collected were analyzed using descriptive and inferential statistics. The study found out that Mn, Zn and Cu are present in liver, tissue and kidney of Cricetomys gambianus while cobalt, cadmium, chromium, lead and nickel are below detection limit. Mn levels ranged between 0.015±0.002, 0.01±0.002 and 0.005±0.003 for liver, tissue and kidney respectively. Zn levels ranged between 0.070±0.016, 0.032±0.013 and0.044±0.006 for liver, tissue and kidney respectively. Cu levels ranged between 0.0087±0.0061, 0.000±0.000 and 0.0057±0.0001 for liver, tissue and kidney respectively. Highest manganese concentration was observed in the liver (0.015±0.002 mg/kg) while highest copper concentration was observed in the liver (0.0087±0.0061 mg/kg).The levels of heavy metals in the liver, tissue and kidney ranged from 1.91±0.00 to 3.96±0.00 mg/kg Zn; 0.15±0.00 to 0.17±0.00 mg/kg Pb; 0.20±0.00 to 1.98±0.00 mg/kg Cu; 0.03±0.00 to 0.27±0.00 mg/kg Cd; and 0.00±0.02 to 0.00±0.00 mg/kg Co; on average. The highest concentration of zinc and copper were found in the liver while manganese is also deposited more in the liver. The Analysis of Variance (ANOVA) test on the distribution and concentrations of all the metals in the liver, tissue and kidney shows that (p<0.05), i.e. there is significant difference in the amount of the elements in this samples and are not safe for human consumption.

Open Access Original Research Article

Assessing the Source of Thallium Contamination in Ground and Surface Waters in the Locality of Yamtenga (Burkina-Faso): Correlation with Some Heavy Metal Ions

Ollé Rodrigue Kam, Corneille Bakouan, Inoussa Zongo, Boubié Guel

International Research Journal of Pure and Applied Chemistry, Page 1-14
DOI: 10.9734/irjpac/2019/v19i430122

Thallium (Tl) is a non-essential element for human being and is considered as a highly toxic trace element at a concentration above 2 µg/L. To assess the source of thallium contamination in ground and surface waters in the locality of Yamtenga village (11°43'35.1'' N and 00°11'50.8'' W, Burkina Faso), chemical analyzes of thallium concentrations in the soils of Yamtenga village along with geological descriptions (geological map and hydrographic watershed map of the studied area) were undertaken. We found thallium concentrations in this area ranging from 1.61 mg / kg to 404.75 mg / kg. A zoned mineralization in thallium, due to the geological structure of the locality, was established in the soils, suggesting that the source of thallium contamination in ground and surface waters in the locality of Yamtenga village is of natural origin. The concentration of some heavy metals (Pb, Zn, Cd, Cu and Mn) were also evaluated in the soils of Yamtenga village and their concentration relationships with thallium were analyzed by the Pearson correlation coefficient based on matrix correlation. Moderate (0.554), low (0.408) and significant (0.999) correlations coefficients were obtained between thallium and lead, zinc, manganese respectively. Significant correlation coefficients (0.788 and 0.791) were also noted between thallium and copper, cadmium respectively. Thallium concentrations in ground and surface waters in this locality are mainly related to the interactions between water and source rocks, thallium being released following some alteration processes with other heavy metals elements especially manganese.

Open Access Review Article

A Review on Nanotechnology: Analytical Techniques Use and Applications

Tassew Belete Bahru, Eyasu Gebrie Ajebe

International Research Journal of Pure and Applied Chemistry, Page 1-10
DOI: 10.9734/irjpac/2019/v19i430117

The combination of nanotechnology with molecular biology, information technology and instrumentation, is opening the door to a new industrial age. The aim of this review article is to summarize the current knowledge of nanotechnology in synthesizing, identifying and characterization of nanomaterials using analytical techniques. Physical and chemical approach synthesis of nanomaterials befalls challenges in the development of analytical techniques used to characterize them. The major techniques include: Transmission Electron Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy, Dynamic Light Scattering, X ray Photoelectron Spectroscopy, X-ray Diffraction, Single Phase Inductively Coupled Plasma Mass Spectroscopy, X ray Fluorescence Spectroscopy, Auger Electron Spectroscopy, X ray Absorption Fine Structure, Capillary Electrophoretic Separations, Magnetic nano particles coupled HPLC and Dynamic light scattering. Nanomaterials have been characterized for the extensive potential applications in optics, electronics, magnetics, and catalysts; chemical sensing, biomedicine, micro reactor, and they have been applied in food, biological, environmental and pharmaceuticals uses. In spite of the extended use of nano particles in diverse consumer products, there is a great concern over the unexpected impact or effects on humans due to exposure.