Earthline Journal of Chemical Sciences
EISSN : 2581-9003
Current Publisher: Earthline Publishers (10.34198)
Total articles ≅ 88
Latest articles in this journal
Earthline Journal of Chemical Sciences, Volume 5, pp 347-361; doi:10.34198/ejcs.5221.347361
(L)-Diiodotyrosine isomers are considered within the realm of density functional theory at the level of B3LYP/6-311+G(d,p). Their zwitter ionic forms are considered as well. All the structures are electronically stable, have exothermic heat of formation and favorable Gibbs free energy of formation values. Within the limitations of the method the zwitter ionic forms are not different from the corresponding parent structures in the vacuum conditions and no hydrogen bonding seems to exist between the NH2 and COOH groups. Some structural, quantum chemical and spectral data have been collected and discussed.
Earthline Journal of Chemical Sciences, Volume 5, pp 329-345; doi:10.34198/ejcs.5221.329345
The present study considers an insensitive explosive, ANTA, (5(3)-amino-3(5)-nitro-1H-1,2,4-triazole) which is optimized within the restrictions of DFT (B3LYP/cc-PVTZ and B3LYP/6-311++G(d,p)). The optimized structure is subsequently subjected to single-point semi empirical MNDO and/or PM3 level of calculations to visualize the effect of electric field which has been set to magnitudes of 0.001 and 0.01 au. Perturbations on the energy and dipole moment are investigated. Also, the directional effect of the field along the axes of inertia of the molecule has been investigated. Generally, the effect of the field is more pronounced along the principle axis of ANTA.
Earthline Journal of Chemical Sciences, Volume 5, pp 307-327; doi:10.34198/ejcs.5221.307327
The low density polyethylene-chitosan nanoparticles (LDPE/CHNP) biocomposite was applied as a biosorbent for the adsorption of Congo red (CR) anionic dye and methyl red (MR) a cationic dye an in single and binary system. The effect of parameter pH, contact time, initial concentration, adsorbent dosage and temperature were studied on the two dyes in single and the binary component system. Kinetic studies showed that adsorption on LDPE/CHNP in a single and binary-component system follows pseudo-second order kinetics. The values of CR in single and binary system were gotten to be 0.9996 and 0.9984 respectively, while the values of MR in single and binary system were 0.9994 and 0.9983 respectively. The adsorption equilibrium study was tested with both Langmuir and Freundlich isotherm and the result showed they agree more with Langmuir have an values for CR in single and binary system to be 0.9995 and 0.9991 respectively, while the values of MR in single and binary system were 0.9954 and 0.9983 respectively; which implies that the adsorptions were more of chemisorption than physiosorption reaction. In the single and binary systems, the result reveals that CR had higher adoption efficiency than MR which could be because the chelation between cations and chitosan chains, which decreased the electrostatic interaction between Methyl red and chitosan nanoparticles of the biocomposite. The LDPE/CHNP biocomposite has proved to be an efficient adsorbent for CR (anionic dye) and MR (cationic dye) in single and two-component system which are frequently encountered composition of industrial effluents.
Earthline Journal of Chemical Sciences, Volume 5, pp 295-306; doi:10.34198/ejcs.5221.295306
Two isomeric methylxanthines, theobromine and theophilline, and their Zn+2 containing composites are considered within the restrictions of density functional theory (B3LYP/ 6-31++G(d,p)). Certain quantum chemical, thermodynamic and spectral data have been harvested, compared and interpreted. The results revealed that theophilline+Zn+2 system is thermodynamically more exothermic, more favorable and electronically stable compared to the analogous system, theobromine+Zn+2.
Earthline Journal of Chemical Sciences, Volume 5, pp 275-294; doi:10.34198/ejcs.5221.275294
Schiff base ligand derived from condensation of 2-aminothiophenol and 2‑thiophenecarboxyldehyde was synthesized and used for the preparation of Ni(II) and Cd(II) complexes. The synthesized ligand and complexes were analyzed by decomposition temperature, solubility, magnetic susceptibility, molar conductance and infrared spectra. The decomposition temperatures of the complexes are 212 and 221°C. Molar conductance values are 16.12 and 12.60 ohm-1cm2mol-1 respectively. New bands appeared in the IR spectra of the complexes in the range of 519 - 475 cm-1 and 462 - 448 cm-1 which indicate υ (M - N) and υ (M - S) vibrations respectively. Magnetic susceptibility measurement indicated that Ni (II) complex is paramagnetic whileCd(II) complex is diamagnetic. The solubility test revealed that all complexes and ligand are soluble in DMSO. The analytical data show the formation of 2:1 metal to ligand ratio for all complexes and suggested the formula [ML2].nH2O. The ligand and metal chelates have been studied for microbial activity using well diffusion method against selected bacteria and fungi. The results signify that Ni(II) and Cd(II) metal complexes inhibit more compared with Schiff base ligand against the same test organisms.
Earthline Journal of Chemical Sciences, Volume 5, pp 261-274; doi:10.34198/ejcs.5221.261274
NTO and TNAZ are two important explosive materials. In the present study, 1:1 molar composite of them are investigated within the constraints of density functional theory at the level of B3LYP/6-31++G(d,p). Certain quantum chemical, physicochemical and spectral properties of the composite have been harvested and compared with the respective values of its components. The formation of composite is exothermic and favorable. The components in the composite undergo certain type of interaction to affect properties of each other.
Earthline Journal of Chemical Sciences, Volume 5, pp 249-260; doi:10.34198/ejcs.5221.249260
Interaction of lithium atom with TEX molecule which is a high density energetic material is considered within the restrictions of density functional theory at the level of UB3LYP/6-31++G(d,p). The results indicate that the lithium atom transfers an electron to TEX causing the rupture of one of C-N bonds of the structure. Some geometrical and quantum chemical data have been collected and discussed. A plausible mechanism has been suggested for the destructive reduction of TEX molecule.
Earthline Journal of Chemical Sciences, Volume 5, pp 241-248; doi:10.34198/ejcs.5121.241248
Under favorable growth conditions, fungi produced aflatoxins. Aflatoxin B1 (AFB1) categorized as a carcinogen is the most toxic and subject of regulation in foods and feeds in many countries. AFB1 contamination has been reported in a wide range of products including cigarette tobacco due to improper processing and storage conditions. This research aim at determining the concentration load of AFB1 mycotoxin in brands of cigarette tobacco commonly consumed in Lapai and Minna metropolis of Niger State Nigeria. Thirty-six (36) brands of cigarette tobacco were purchased in open markets in Minna and Lapai towns of Niger state, Nigeria. Residual AFB1 was extracted from the sample using standard procedures. HPLC analysis was used for the mycotoxin quantification. The result showed that all cigarette samples produces AFB1 with a concentration of 302 µg/mL and 18 µg/mL as the highest and lowest AFB1 concentration respectively for the local – Nigeria brands compared to 166 µg/mL and 8 µg/mL AFB1 concentration observed for the foreign brands. The findings from this study provide sufficient levels of contamination to pose significant health hazard for the consumer of the tobacco. Careful processing and storage is therefore advocated to eliminate or reduce the mycotoxin contamination of the cigarette brands.
Earthline Journal of Chemical Sciences, Volume 5, pp 231-240; doi:10.34198/ejcs.5121.231240
Ziziphus spina found in the tropical regions of the world is a small tree capable of resisting heat and drought. The edible portion of the fruit is widely preserved as feed for human and animal especially in drought and famine ravaged nations of the world. The edible fruit of Z. spina were procured from a local market in Gusau, Zanfara State North-Western Nigeria in October 2019. They were prepared for proximate and mineral analyses using standard analytical methods. The results showed the percentage (%) moisture, ash, crude lipid, crude protein, crude fibre and total carbohydrate contentas3.13, 15.22, 3.11, 11.12, 6.45 and 64.10 respectively while the calorific values was reported to be 328.87kcal/100g.The elemental analyses revealed that potassium and copper were the most and least abundant element with concentrations of 256.12 and 2.37 mg/100 g dry weight respectively. The findings from this study reveal that Z.spina fruit contains important mineral elements that would possibly improve on the proper metabolic activity and therefore could improve on the health standard if properly utilized.
Earthline Journal of Chemical Sciences, Volume 5, pp 207-219; doi:10.34198/ejcs.5121.207219
Mining activities have long been recognized as a major source of environmental contamination associated with heavy metals. In this study, ten (10) trace metals namely As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb and Zn were analysed from water (stream, river and borehole) and soil (surface and sub-soil) samples collected from around the artisanal and small scale gold mining site within the vicinity in Kuchiko-Hausa, Gurara LGA, Niger State, Nigeria using Atomic Absorption Spectroscopy. The result from the water and soil samples showed the while all the investigated trace metals were absent from all the water samples, Hg was only found with concentration of 0.006 and 0.0053 mg/mL for the stream and river water samples, the soil samples showed the presence of all the trace metals except Cd and Co with As and Cr found only in the surface soil. All detected trace metals in the samples were all lower than the WHO permissible limits. Periodic and systematic study of the investigated and other metals concentrations is therefore recommended since long-term exposure of these metals poses significant health risk for human, animals and plants.