South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie最新文献_第8页

Templated Cross-linked Nanoporous Starch 模板化交联纳米多孔淀粉

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/V73A19

Somayeh Oftadehgan, A. P. Marjani, J. Khalafy, A. Zamani

引用次数: 0

Understanding the Link Between the Detection Limit and the Energy Stability of Two Quercetin-Antimony Complexes by Means of Conceptual DFT 用概念DFT了解两种槲皮素-锑配合物的检出限与能量稳定性的关系

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/V73A17

Naceur Benhadria, T. Attar, Boulanouar Messaoudi

{"title":"Understanding the Link Between the Detection Limit and the Energy Stability of Two Quercetin-Antimony Complexes by Means of Conceptual DFT","authors":"Naceur Benhadria, T. Attar, Boulanouar Messaoudi","doi":"10.17159/0379-4350/2020/V73A17","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/V73A17","url":null,"abstract":"In view of the importance of quercetin and its derivatives in trace metal analyses, two organometallic complexes formed between quercetin (Q) and quercetin-5-sulfonic acid (QSA) with antimony metal, were theoretically studied via density functional theory (DFT) calculations. In this study, the concept of detection limit in electroanalysis was correlated to quantum chemical calculations for antimony trace analysis in aqueous solution by using Q and QSA as ligands. Based on two previous reports, the study was carried out experimentally using polarography where the working electrode was a dropping mercury electrode. The DFT calculations were performed with B3LYP and LSDA functionals as implemented in Gaussian 09 program and by employing the 6-31G(d) and 3-21G(d) basis sets, respectively. The results show a very strong relationship between the total energy of antimony complexes and the detection limit; thus, the more stable complex has a better detection limit value. Based on the Fukui functions, the calculated parameters such as local nucleophilicity indices and HOMO-1 electronic density of the ligands show a high interaction of antimony ion (III) with quercetin-5-sulfonic acid than that with quercetin. This finding was in good accord with the experimental results.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"45 1","pages":"120-124"},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Flower of Typha latifolia as a Low-cost Adsorbent for Quantitative Uptake of Multiclass Pesticide Residues from Contaminated Waters 作为一种低成本吸附剂定量吸收污染水体中多类农药残留的风叶花

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a4

Tura Gemechu, Teshome Toleha, Megussie Megersa

{"title":"Flower of Typha latifolia as a Low-cost Adsorbent for Quantitative Uptake of Multiclass Pesticide Residues from Contaminated Waters","authors":"Tura Gemechu, Teshome Toleha, Megussie Megersa","doi":"10.17159/0379-4350/2020/v73a4","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a4","url":null,"abstract":"The quantitative removal of atrazine, diazinon, chlorothalonil, ametryn, chlorpytrifos and dimethametryn from contaminated water was studied using flower of the Typha latifolia. The surface chemistry of this adsorbent was analyzed by FT-IR and the adsorption efficiency was studied using batch adsorption technique. The potential experimental parameters studied were pH (5–9), the dose of adsorbent (0.1–0.5 g), contact time (100–140 min), shaking speed (100–300 rpm) and initial pesticide concentration (3.15–100 μg L). The effects of concentration and contact time at the optimum conditions were used to study equilibrium and kinetic models for pesticide sorption. Results of the sorption equilibria were found to fit better to the Langmuir isotherm model than the Freundlich adsorption model indicating monolayer homogeneous surface conditions. On the other hand, kinetics of all pesticides sorption on the adsorbent was well defined by the pseudo-second-order model. The results obtained showed that the use of this plant be considered as one of the promising, natural, easily accessible and low-cost adsorbent for efficient and quantitative removal of pesticides from contaminated water.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Development of a Thiol-capped Core/Shell Quantum Dot Sensor for Acetaminophen 硫醇封端对乙酰氨基酚核壳量子点传感器的研制

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-06-05 DOI: 10.17159/0379-4350/2019/V72A14

H. Montaseri, Oluwasesan Adegoke, P. Forbes

引用次数: 4

Comparative effects of silver nanoparticles, sucrose and sodium chloride as osmotic solutions for tomato slices: antioxidant activity, microbial quality and modelling with polynomial regression model 纳米银、蔗糖和氯化钠作为渗透溶液对番茄片的比较效果:抗氧化活性、微生物质量和多项式回归模型建模

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-02-26 DOI: 10.17159/0379-4350/2019/V72A4

L. Azeez, A. Lateef, A. Wahab, A. Adejumo, K. Raji

{"title":"Comparative effects of silver nanoparticles, sucrose and sodium chloride as osmotic solutions for tomato slices: antioxidant activity, microbial quality and modelling with polynomial regression model","authors":"L. Azeez, A. Lateef, A. Wahab, A. Adejumo, K. Raji","doi":"10.17159/0379-4350/2019/V72A4","DOIUrl":"https://doi.org/10.17159/0379-4350/2019/V72A4","url":null,"abstract":"This study has reported comparative effects of silver nanoparticles (AgNPs), sucrose and sodium chloride as osmotic solutions on antioxidant activity and microbial quality of 10 mm tomato slices. 40 g of tomato slices were dehydrated osmotically (OD) at different temperatures (60, 70 and 80 °C) and time (30, 60, 90, 120 150 and 180 min).Water loss, solid impregnation, water and solid diffusivities of tomato slices were found to increase with increase in solution temperatures and concentrations with AgNPs having the greatest influence. Antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl increased with increase in solution concentrations but decreased with increase in temperature. Three-wayANOVA(R2=0.998) revealed additive statistically significant effects of osmotic agents, concentrations and temperatures on antioxidant activity; F(8,54)=67.854,P=0.00. Polynomial regression analysis with response surface methodology validated experiments such that for each unit increase in concentration and temperature, antioxidant activity increased with good coefficients of determination; sucrose (R2 = 0.87), NaCl, (R2 = 0.89) and AgNPs (R2 = 0.91). Potato dextrose and nutrient agars were used for isolating and identifying microorganisms in OD tomato slices. Tomato slices dehydrated with AgNPs had the highest microbial inhibition of fungi with growth occurring after 7 days, unlike in treatments with sucrose and NaCl where fungal growth appeared after 2 and 5 days, respectively. Aspergillus niger was the most prevalent fungus. It can be concluded that AgNPs may serve as a viable means to dehydrate and preserve tomatoes without loss of antioxidant activity. Keywords : Osmotic dehydration, polynomial regression, response surface, antioxidant activity, three-way ANOVA, silver nanoparticles.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47292079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Selective Removal of Organonitrogen Compounds in Fuel using Functional Polybenzimidazole Nanofibres: A Combined Experimental and Theoretical Study 功能化聚苯并咪唑纳米纤维选择性去除燃料中有机氮化合物的实验与理论结合研究

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-01-01 DOI: 10.17159/0379-4350/2019/V72A12

M. S. Abdul-quadir, R. V. D. Westhuizen, W. Welthagen, E. Ferg, Z. Tshentu, A. Ogunlaja

引用次数: 2

Liquid Chromatographic Determination of Dexamethasone and Fluoroquinolones; in vitro Study 液相色谱法测定地塞米松和氟喹诺酮类药物体外研究

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-01-01 DOI: 10.17159/0379-4350/2019/v72a16

Nawab Sher, N. Fatima, S. Perveen, F. Siddiqui

引用次数: 4

Synthesis of Indeno[1,2-b]benzofurans using TPAB as Highly Efficient and Recoverable Catalyst 以TPAB为高效可回收催化剂合成茚二[1,2-b]苯并呋喃

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-01-01 DOI: 10.17159/0379-4350/2019/v72a21

A. P. Marjani, J. Khalafy, Somayeh Akbarzadeh

引用次数: 4

Production and Characterization of Carbon Molecular Sieves from Bituminous Lafia-Obi Nasarawa Coal by Pore Size Modification with Spent Engine Oil 废机油孔径改性烟煤碳分子筛的制备及表征

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-01-01 DOI: 10.17159/0379-4350/2019/V72A3

E. Bala, O. R. Momoh, B. Aderemi, B. J. El-Yakubu

{"title":"Production and Characterization of Carbon Molecular Sieves from Bituminous Lafia-Obi Nasarawa Coal by Pore Size Modification with Spent Engine Oil","authors":"E. Bala, O. R. Momoh, B. Aderemi, B. J. El-Yakubu","doi":"10.17159/0379-4350/2019/V72A3","DOIUrl":"https://doi.org/10.17159/0379-4350/2019/V72A3","url":null,"abstract":"In this work, a carbon molecular sieve (CMS) was produced from a bituminous Lafia-Obi Nasarawa coal. An initial activated carbon (AC) sample was prepared via chemical activation from the coal, from which the CMS samples were then produced through heat treatment processes and carbon deposition fromspent engine oil. Spent engine oil was pyrolyzed in order to deposit carbon at the pore mouth of coal-based AC to yield CMS. The effect of reaction temperature and holding time variation on the surface area, micropore pore volume and pore size of CMS was studied. Reaction temperature was varied at 400, 550 and 700 °C while holding time was varied at 30 and 60 min. The Brunauer–Emmett–Teller (BET) method was used to calculate the surface areas, while the Dubinin–Radushkevich (DR) and Horvath-Kawazoe (HK) methods were used to determine the micropore volumes and pore sizes of the AC and CMS, respectively. The CMS sample with the largest BET surface area (5.824 m2 g–1), DR micropore volume (0.172 cm3 g–1) and HK pore size (6.317 A) were obtained at 700 °C reaction temperature and 60 min holding time. In addition to this, a molecular sieving ability test to separate benzene from a mixture of benzene and o-xylene in solution was carried out on the AC and CMS, with the CMS having a selective benzene percentage uptake of 61.36 %. Keywords : Activated carbon (AC), carbon molecular sieves (CMS), carbon deposition, reaction temperature, holding time.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetics, Thermodynamics and Isothermal Modelling of Liquid Phase Adsorption of Methylene Blue onto Moringa Pod Husk Activated Carbon 辣木荚壳活性炭液相吸附亚甲基蓝的动力学、热力学及等温模拟

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2019-01-01 DOI: 10.17159/0379-4350/2019/v72a34

G. Adebayo, W. Jamiu, H. Okoro, F. Okeola, A. Adesina, O. Feyisetan

引用次数: 8