Журнал химических наук

Phthalate esters which are plasticizers in plastics, other polymers, blood bags and infusion tubes are known to leach extensively into the content. Phthalate esters have been implicated as endocrine disruptors in humans. Therefore, clinically; phthalate esters pose serious health risk, as transfused patients are vulnerable to phthalate esters contamination. In this study the concentrations of some phthalate esters and phthalate esters metabolites in blood serum, urine and breast-milk of some transfused nursing mothers. The study was carried out in some major hospitals in Ibadan metropolis after the receipt of ethical approval. Blood, urine and breast milk samples were obtained from twenty consented transfused nursing mothers and the samples were obtained in replicates. Hexane: dichloromethane 87.5:12.5 v/v was used to extract blood serum. Hexane: dichloromethane 87.5:12.5 v/v was used to extract urine. Hexane: diethyl ether, 50:50 v/v was used to extract breast-milk sample. All extractions were done using ultrasonicator. The extracts were cleanup respectively in a column of silica gel and eluted with hexane: acetonitrile 99.3:0.7 v/v, the cleanup extract was analyzed using HPLC-UV. The concentration of diethyl phthalate was in the range from not detected (nd)-3.03, nd-0.30 and nd-0.94 μg/ml; in breast-milk, urine and blood serum respectively. Dipropyl phthalate ranged from 0.09-1.55, nd-1.2 and nd-7.68 μg/ml; in breast milk, urine and blood serum respectively. Dibutyl phthalate ranged from 0.07-2.22, nd-1.2 and nd-10.74 μg/ml; in breast-milk, urine and blood serum respectively. Monobutyl phthalate ranged from 0.62-15.04, nd-3.2 and nd-7.45 μg/ml; in breastmilk, urine and blood serum respectively. Mono-2-ethyl-5-oxo-hexyl phthalate ranged from 0.84-4.29, nd-1.5 and nd-14.68 μg/ml; in breast milk, urine and blood serum respectively. Level of phthalate esters and metabolites in the samples were high; which is suggestive that the infusion tubes and blood bags may be one of the major clinical sources of phthalate esters contamination in transfused patients.

The bark of neem tree (Azadirachta indica) was used in this study as bio-indicator to monitor heavy metal pollution in Katsina Township. Barks were sampled from four sites in Katsina Township, which include; Katsina Steel Rolling Company Round-about (Site A), Kofar Kwaya Round-about (Site B), Kofar Yandaka Round-about (Site C) and Nigeria Army Barrack, Natsinta (Site D). The samples were analyzed for Iron (Fe), Manganese (Mn), Copper (Cu), Lead (Pb), Cobalt (Co), Chromium (Cr), Nickel (Ni) and Zinc (Zn) using Atomic Absorption Spectrophotometry (AAS). The results obtained revealed Fe (52.50 μgg-1-196.25 μgg-1), Mn (19.50 μgg-1-34.25 μgg-1), Zn (2.41 μgg-1-8.43 μgg-1), Cr (<1.00 μgg-1-18.75 μgg-1), Co (3.01 μgg-1-11.50 μgg-1), Pb (<1.00 μgg-1-3.50 μgg-1), Ni (1.00 μgg-1-4.25 μgg-1) and Cu (0.13 μgg-1-2.75 μgg-1) across the four sites. The order of metal concentration from each site is site A (Fe>Mn>Cr>Co>Zn>Ni>Pb>Cu), site B (Fe>Mn>Co>Zn>Ni>Pb>Cr>Cu), site C (Fe>Mn>Zn>Co>Pb>Ni>Cu>Cr) and site D (Fe>Mn>Co>Cu>Zn>Ni>Cr>Pb). The heavy metal burdens from site A are the highest while those from site D are the least. The result also indicated a correlation between the heavy metal concentrations and distance of each site from the source of contamination with the exception of Cu, Pb and Zn concentrations. Amidst the heavy metal analyzed Fe has the highest level while Cu has the least. From this study the heavy metal load does not pose any immediate health risk to the inhabitants and other lives in Katsina Township

The measurements of vanadyl sulfate conductance have been in mixed solvent with methanol-H2O (MeOH-H2O), and N, N- Dimethyl formamide (DMF-H2O) in different mass fraction 10%, 30% and 50% at four different temperatures from 298.15 to 313.15K. The experimental data have been analyzed by using the Fuoss-Shedlovsky extrapolation technique. Estimated thermodynamic parameters for association were calculated and discussed. These parameters such as molar conductance (Λm), limiting molar conductance (Λ0), Walden product (Λ0 η0), ionpair association constant (KA), the activation energy for the transport process (Ea) and the standard thermodynamic parameters for association (ΔGoA, ΔHoA and ΔSoA). The different thermodynamic parameters for Vanadyl sulfate were estimated and compared the result of organic solvent over wide range of temperature.

In this study, three modeling techniques based on artificial intelligence were used to predict the removal percent of lead(II) ions from the aqueous solution. These models include Artificial Neural Network (ANN), Fuzzy Inference System (FIS) and Adaptive Neuro-Fuzzy Inference System (ANFIS). Magnetic graphene adsorbent supported on nylon 6 was used for removing lead(II) ions. Optimal conditions for the experimental parameters were performed using the Taguchi methodology. The analysis of variance (ANOVA) test at the 95% confidence level was applied to the results of these models which suggested there were no significant differences among these models.

As a global trend, safety has become the number one priority in all industries worldwide. This leads any organization either It is in the design phase or already in production to design or modify respectively it’s layout and Installations to comply with safety standards. One of the most important hazards that are common in most industries, either it is petrochemical, non-petrochemical or even FMCG (Food Manufacturing and Customer Goods) industries, is the Explosion Hazard. According to the most recent fire statistics from the National Fire Protection Association (NFPA): An average of 37,000 fires occurs at industrial and manufacturing properties every year. These incidents resulted in 18 civilian deaths, 279 civilian injuries and $1 billion in direct property damage. It is a smart step to take a preventive action towards explosions, rather than a corrective action. As a matter of fact, as every industry requires a type of fuel – which is usually flammable- to run its operations, one of the most common units in all industries nevertheless what category it falls into, is the LPG/SNG (liquefied Petroleum Gas/Synthetic Natural Gas) unit. As much as this unit is important and mandatory to any industry, it is considered one of the most potential areas of explosions as well. Hazard area classification (HAC) is a study in which an industrial area is divided into zones according to the probability of the presence of combustible or flammable material in that zone. There are different standards for applying the study, and different outcomes according to the condition of the zone, this includes the material, pressure and temperature. In this paper we will discuss the HAC study of one of the most common units in industry, which is the LPG/SNG system. The aim of the study is to be a good reference for industries that have this unit or have a need to install it and needs to apply a preventive HAC study on it to mitigate explosion risk.

The depletion of fossils fuels and increasing demand of conventional energy worldwide had been the main concern of scientist nowadays, in the process to find the sustainable alternative. The biodiesel appears to be promising alternative. The optimization of biodiesel production from Jatropha seed oil using sulphated zirconia as catalyst was investigated based on Box-behnken design. The optimum yield 97.91% was obtained at 1:8 oil to methanol ratio, 60°C reaction temperature, 2.15 hrs, and 2 w/w% catalyst loads. The response surface regression shows the variables constant, oil to methanol ratio, reaction temperature, reaction time, reaction temperature*reaction temperature and methanol to oil*catalyst load were significantly affect the biodiesel yield. The model adequately accounts for the empirical relationships between biodiesel and process variables.