Archives

Volume 8 Number 2 June 2023

Reaction Mechanism and Kinetics Study of Wheat Polysaccharide via Modified Reductor Technique in Bead Making Process


Authors: C. A. Idibie ; K. J. Awatefe ; P. D. Clark
Pages: 40-44
DOI: doi.org/10.32861/ajc.82.40.44
Abstract
The reaction mechanism and kinetics investigation of the substitution of titanium in wheat flour polysaccharide (referred to here as titaniumation) in aqua medium during bead making process was carried out. The use of the Modified Reductor Technique was implored to study the reaction kinetics. The study was carried out at varying temperatures between 25 – 70oC. The study showed that the titaniumation of the wheat polysaccharide molecules increased with time and temperature. Hence, at 25oC, the degree of titaniumation (DT) of the ring increased from 0.41 % to 0.49 % and at elevated temperature of 70oC, DT increased from 0.58 to 0.94 % as time progressed from 30 to 210 mins, respectively, while keeping both amount of wheat polysaccharide and TiO2 constant, and thus achieving >1.9-fold. This also implies that the titaniumation of wheat polysaccharide using TiO2 is favourable at elevated temperature. The study was able to reveal that the reaction mechanism of the titaniumation of the polysaccharide molecules is an electrophilic substitution reaction, favouring the ortho position, while the kinetics study showed that the titaniumation reaction is of first order reaction.

Design a Cu2+ Fluorescent Probe Derived from Pyrene


Authors: Zhang Shu-ting ; Lin Xiao-ying ; Xiao Ling, et. al.
Pages: 36-39
DOI: doi.org/10.32861/ajc.82.36.39
Abstract
A Cu2+ probe based on pyrene derivatives was introduced. Compared to other metal ions, it exhibited a highly selective and sensitive fluorescence response to Cu2+.


Chemical Analysis of Essential Trace Elements in Wastewater Samples Collected from Four Different Mines


Authors: Alegbe ; John ; Moronkola, et, al.
Pages: 30-35
DOI: doi.org/10.32861/ajc.82.30.35
Abstract
Mine water contains trace heavy metals which are some essential trace elements in high concentrations causing the pollution of nearby water bodies, related ground waters and soils degradation. The aim of the study is to identify and quantify the essential trace elements present in the different mine water samples and their level of toxicity. Digestion technique was employed to pretreat the mine wastewater before analysis. Physicochemical analysis was conducted for pH, electrical conductivity (EC), total dissolved solids (TDS), and salinity. The samples collected from four different locations are Sample A (Gold mine), Sample B (Copper mine), Sample C (Iron mine), Sample D (Tin mine). The raw or untreated mine water samples were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed the essential trace elements present in all the mine water samples are Mn, Cu, Fe and Zn. Cu is highly concentrated in copper (73.87 mg/L) and tin (2.09 mg/L) mine water while Fe is dominant in water samples collected from gold (7.19 mg/L) and iron (13.12 mg/L) mine. In conclusion, the essential trace elements Mn, Cu, and Fe present in all the mines are very high and can be harmful to human life in the environment but the concentrations of Zn in the entire mine water samples are within the permissible level of standard drinking water and hence it can pose no threat to human life.

Design of Highly Selective Cu2+ Fluorescent Probe Based on Pyrene Derivatives


Authors: Lin Xinyu ; Zhang Jun ; Yu Chunwei
Pages: 25-29
DOI: doi.org/10.32861/ajc.82.25.29
Abstract
A new probe P was synthesized and characterized from pyrene formaldehyde. The probe showed good selectivity for Cu2+ over other metal ions in ethanol-water solution (Vethanol:Vwater=3.5:1.5, pH 6.5, 0.02 M HEPES). With the increasing of Cu2+ concentration (2-10 μM), the P-Cu2+ system displayed excellent linear relationship at 464 nm with the detection limit down to 0.66 μM.