South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie最新文献

Trace nickel analysis in water samples via paper-based devices coupled with co-precipitation 用纸基共沉淀法分析水样中痕量镍

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a01

Abdellah Muhammed, A. Hussen, T. Kaneta

{"title":"Trace nickel analysis in water samples via paper-based devices coupled with co-precipitation","authors":"Abdellah Muhammed, A. Hussen, T. Kaneta","doi":"10.17159/0379-4350/2023/v77a01","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a01","url":null,"abstract":"A simple, fast, low-cost and sensitive microfluidic paper-based analytical device (u-PADs) integrated with the co-precipitation enrichment procedure was developed to analyse Ni(II) in tap and mineral water samples. The impacting factors, including pH, centrifugation (5 min at 4000 rpm), and amounts of reagents were optimized. The limit of detection of 0.009 mg L-1 and linear range of 0.03-2.00 mg L-1 were achieved with good intra- and inter-day precision (4.7 and 5.6% RSD, respectively). The recovery tests were conducted by spiking tap and mineral water samples and analyzed using the u-PADs after co-precipitation enrichment. The results obtained by the proposed method were validated by inductively coupled plasma-optical emission spectrometry (ICP-OES). The recoveries of the present method and ICP-OES were ranged from 92.4-106.8% and 92.9-97.2%, respectively. The two sets of (u-PADs and ICP-OES) results were in good agreement, as a paired t-test indicated no significant differences. The proposed method could be utilized for analyzing trace levels of Ni(II) in water samples in developing countries where the availability of conventional analytical instruments are significant problems.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464154","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

Mononuclear discrete Ag(I) complexes of aryl substituted (E)-N-phenyl-1-(pyridin-3-yl)methanimine: In vitro biological activities and interactions with biomolecules 芳基取代(E)- n-苯基-1-(吡啶-3-基)甲亚胺的单核离散Ag(I)配合物:体外生物活性及与生物分子的相互作用

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a08

A. Adeleke, S. Islam, K. Olofinsan, V. Salau, B. Omondi

{"title":"Mononuclear discrete Ag(I) complexes of aryl substituted (E)-N-phenyl-1-(pyridin-3-yl)methanimine: In vitro biological activities and interactions with biomolecules","authors":"A. Adeleke, S. Islam, K. Olofinsan, V. Salau, B. Omondi","doi":"10.17159/0379-4350/2023/v77a08","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a08","url":null,"abstract":"The synthesis of three pyridinyl imines (L1-L3) with electron-donating and electron-withdrawing functional groups, as well as their silver(I) complexes (1a-3a, 1b-3b and 1c-3c), resulted from our ongoing search for novel metallodrugs with potential pharmacological activity. Various analytical and spectroscopic analyses were used to characterize the Ag(I) complexes. The single crystal X-ray diffraction analysis of complexes 3a and 3b in the solid state confirmed their linear geometry around the Ag(I) center. In vitro antibacterial properties of the complexes evaluated using the minimum inhibitory concentration (MIC) method revealed that complexes containing either a Me- or an F-substituent exhibited greater activity. The ferric-reducing antioxidant power (FRAP) experiment revealed that complexes with hydroxyl substituents have high antioxidant potential. These complexes with IC50 values ranging from 0.86 to 2.47 mg mL-1 outperformed ascorbic acid, with an IC50 of 2.68 mg mL-1. The reported complexes bound to CT-DNA via intercalation mode with significant binding constants for complexes whose ligands bore the OH- substituent. Bovine serum albumin (BSA) binding affinity to the complexes ranges from moderate to high. The studied complexes with methyl substituents are promising anti-cervical cancer candidates.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464397","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: 1

The coordination behaviour of 2-((E)-(ferf-butylimino)methyl) phenol towards lanthanide nitrate and chloride salts 2-((E)-(ferf-butylimino)甲基)苯酚对硝酸镧和氯化物盐的配位行为

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a06

Kwakhanya Mkwakwi, E. Hosten, R. Betz, A. Abrahams, Tatenda Madanhire

{"title":"The coordination behaviour of 2-((E)-(ferf-butylimino)methyl) phenol towards lanthanide nitrate and chloride salts","authors":"Kwakhanya Mkwakwi, E. Hosten, R. Betz, A. Abrahams, Tatenda Madanhire","doi":"10.17159/0379-4350/2023/v77a06","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a06","url":null,"abstract":"Five novel complexes were prepared by reacting 2-((E)-(tert-butylimino)methyl)phenol (HL2) with Ln(NO3)3xH2O (Ln = Gd and Dy ; x = 6 and 5, respectively) and LnCl3-6H2O (Ln = Nd, Gd and Dy). The crystal structures of the former two Ln(III) nitrate complexes are isostructural and the coordination sphere is composed of three monodentate HL2 ligands bonded to the metal centre through the phenolic oxygen atom and three nitrate ions coordinated in a bidentate fashion. Both complexes are nine-coordinate and SHAPE analysis reveals that they adopted a muffin polyhedra geometric type. The average Ln-Onitrate and Ln-Ophenolate bond lengths are 2.5059 and 2.2816 A, respectively. The complexes derived from the chloride salts exhibited an octahedral geometry with four monodentate Schiff base ligands [Ln-Ophenolate distances range from 2.229(4) to 2.2797(18) A] coordinating in the equatorial positions and two chloride ions [average Ln-Cl bond length is 2.6530 A, and average Cl-Ln-Cl angles is 180o] in axial positions. The ligand coordinated through the phenolate oxygen with the phenolic proton migrating to the imino nitrogen to give a zwitterionic form of the ligand. There are weak C-H-Cl interactions present and O-H-N hydrogen bonds are also observed in the crystal packing.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464318","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

A simple method for colourimetric determination of silver using a home-made double beam photometer 用自制双光束光度计测定银的简单比色法

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a03

M. Saadati

{"title":"A simple method for colourimetric determination of silver using a home-made double beam photometer","authors":"M. Saadati","doi":"10.17159/0379-4350/2023/v77a03","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a03","url":null,"abstract":"The present study proposes a simple and inexpensive photometric method for the selective determination of Ag(I). This method employed a home-made double beam photometer for the determination of silver ions based on an optode sensor prepared by immobilization of 5-(P-Dimethylaminobenzylidene)-rhodanine (PDR) on triacetyl cellulose (TAC) membrane. Two green LEDs as sources of light and light-dependent resistors (LDRs) as detectors were used in the proposed device. The LEDs are turned on by a programmable microcontroller that receives signals from light passed through the sensor, and the absorbance is calculated and displayed on a Liquid-crystal display (LCD) screen. With the optimum conditions, the calibration plot was linear in the concentration range of 0.5-6 μg mL-1. For five replicate determinations of 2 μg mL-1 Ag(I) and the related detection limits, the relative standard deviations were 2.29% and 0.25 μg mL-1, respectively. The method was applied successfully for determining silver in a silver sulphadiazine cream, a radiology effluent, and radiology film samples and the results obtained were in good agreement with those of the standard flame atomic absorption spectroscopy (FAAS) method.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464245","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

Attitudes to science when doing kitchen chemistry at science clubs 在科学俱乐部做厨房化学时对科学的态度

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a10

J. Sewry, A. Ngqinambi, K. Ngcoza

{"title":"Attitudes to science when doing kitchen chemistry at science clubs","authors":"J. Sewry, A. Ngqinambi, K. Ngcoza","doi":"10.17159/0379-4350/2023/v77a10","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a10","url":null,"abstract":"The South African grade 9 Natural Sciences curriculum suggests the use of everyday science to introduce the usefulness and the relatability of science to learners. Many learners, however, seem to have a negative attitude towards science learning and science as an entity. This study is an intervention that sought to ascertain the attitudes of grade 8 and 9 learners in under-resourced schools in South Africa after they had carried out kitchen chemistry hands-on practical activities at science clubs in under-resourced township schools. The learners were interviewed about their experiences, and university student volunteers at the science clubs were also interviewed. An inductive-deductive thematic approach was used to analyse the qualitative interview data. The findings of the study revealed that the learners had a more positive attitude toward science after they had been engaged in the kitchen chemistry hands-on practical activities. Additionally, the integration of everyday knowledge promoted conceptual understanding and improved the performance of the learners. The interviews with the student volunteers revealed aspects that they thought would improve learners' attitudes to science. Science clubs run by university student volunteers could assist in promoting a positive attitude to science among learners.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464417","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

A journey of 10 years in analytical method development and environmental monitoring of pharmaceuticals in South African waters 为期10年的南非水域药物分析方法开发和环境监测之旅

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a11

L. Madikizela

{"title":"A journey of 10 years in analytical method development and environmental monitoring of pharmaceuticals in South African waters","authors":"L. Madikizela","doi":"10.17159/0379-4350/2023/v77a11","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a11","url":null,"abstract":"Apart from the studies which reported the occurrence of steroid hormones and antibiotics in wastewater treatment plants (WWTPs) back in 2004, 2007 and 2012, the evidence for monitoring of pharmaceuticals in South African water bodies intensified from 2014. Therefore, this study reviewed the analytical methods developed and applied in South Africa for the purpose of monitoring pharmaceuticals and their metabolites in water. At the same time, pharmaceuticals and their metabolites detected in South African waters are reviewed. To date, there is over 100 pharmaceuticals detected in South African waters with most studies focussing on quantitative analysis of non-steroidal anti-inflammatory drugs (NSAID), antibiotics, antiretroviral drugs and carbamazepine. Various sources of pharmaceuticals in the environment are reported, with WWTPs found as the major contributor to their occurrence in South African rivers. Notably, a NSAID, ibuprofen, with concentrations found exceeding 100 μg L-1 in selected WWTPs has also been found at high levels reaching 60 μg L-1 in river water. Mostly, pharmaceuticals detected in wastewater are also reported in corresponding rivers. The present review details pharmaceuticals that should be included in environmental monitoring studies performed in South Africa, while also identifying areas for future research through the research gap analysis.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464483","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

Effects of calcination temperature of eggshell-derived CaO as a catalyst for biodiesel production from waste cooking oil 蛋壳源氧化钙煅烧温度对废食用油制备生物柴油的影响

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a05

R. Alsaiari, E. Musa, M. Rizk

{"title":"Effects of calcination temperature of eggshell-derived CaO as a catalyst for biodiesel production from waste cooking oil","authors":"R. Alsaiari, E. Musa, M. Rizk","doi":"10.17159/0379-4350/2023/v77a05","DOIUrl":"https://doi.org/10.17159/0379-4350/2023/v77a05","url":null,"abstract":"Biodiesel is considered to be more friendly to the environment than petroleum-based fuels, cheaper and capable for producing greener energy which contributed positively in boosting bio-economy. In this work, waste cooking oil (WCO) is converted into biodiesel utilizing a waste eggshell (CaO) nano-catalyst in an effort to discover environmentally beneficial and economically viable processes for social and economic development. The eggshell-based CaO catalyst developed for the production of ecologically friendly biodiesel at a reduced price is calcined at temperatures between 600 and 1100 °C. The synthesized catalysts were assessed in terms of their physical and chemical qualities via BET, TGA and XRD analysis. This revealed that, besides displaying exceptional transesterification activity, the catalyst synthesised at 950 °C also offered the greatest biodiesel yield. Transesterification, used in biodiesel generation, was used to evaluate the catalytic performance of manufactured catalysts under several reaction circumstances. Under prime reaction conditions i.e., a reaction time of 3 hours, an ethanol-oil molar ratio of 9:1, and a catalyst amount of 4 wt.%, it was ascertained that a catalyst which had calcined at 950 °C demonstrated excellent transesterification activity and delivered a ceiling yield of 88% fatty acid ethyl esters. The production of FAME was confirmed by using gas chromatography-mass spectroscopy (GC-MS). Fuel properties of fatty acid ethyl ester complied with ASTM D 6751 which indicated that it would be an appropriate alternative form of fuel.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67464300","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

Re-screening and preliminary in vitro evaluation of resorcinol based Hsp90 inhibitors for potential protocidal activity 间苯二酚类Hsp90抑制剂的重新筛选和体外初步评价

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a04

T. Umumararungu, M. Isaacs, H. Hoppe, E. Goosen, S. Khanye

引用次数: 0

Quinoline-benzofuran and quinoline-benzothiophene derivatives as antiplasmodium agents 喹啉-苯并呋喃和喹啉-苯并噻吩衍生物作为抗疟原虫剂

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a02

Jonathan B Hay, K. A. Villiers, Dale Taylor, Tania Olivier, W. V. Otterlo, Margaret AL Blackie

引用次数: 0

Statistical evaluation of the uncertainties in the characterization of South African mine tailings 南非矿山尾矿特征不确定性的统计评价

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2023-01-01 DOI: 10.17159/0379-4350/2023/v77a07

K. Mashale, B. May, J. Sehata, J. Tshilongo, L. Chimuka

引用次数: 0