Macedonian Journal of Chemistry and Chemical Engineering最新文献_第3页

The electrochemical reduction of hydrogen peroxide on a palladium-amorphous carbon composite in an alkaline medium 碱性介质中过氧化氢在钯-无定形碳复合材料上的电化学还原

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-12-24 DOI: 10.20450/mjcce.2023.2776

Jelena Čović, Valentin Mirčeski, Aleksandra Zarubica, Aleksandar Bojić, Miloš Marinković, M. Ranđelović

引用次数: 0

The influence of different yeast strains and yeast nutrients on the aroma of Krstač and Žižak wines 不同酵母菌株和酵母营养成分对 Krstač 和 Žižak 葡萄酒香气的影响

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-12-24 DOI: 10.20450/mjcce.2023.2777

Valerija Madžgalj, Aleksandar Petrović, V. Tešević, B. Anđelković, Ivana Sofrenić

{"title":"The influence of different yeast strains and yeast nutrients on the aroma of Krstač and Žižak wines","authors":"Valerija Madžgalj, Aleksandar Petrović, V. Tešević, B. Anđelković, Ivana Sofrenić","doi":"10.20450/mjcce.2023.2777","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2777","url":null,"abstract":"Krstač and Žižak are autochthonous grape varieties grown in Montenegro. Although international varieties are more popular, the autochthonous varieties are very important, especially for countries developing tourism. The fermentation aromas produced during alcoholic fermentation contribute significantly to wine quality. The effects of yeasts (Saccharomyces cerevisiae and Saccharomyces bayanus) and yeast nutrients (Fermaid E and Fermaid O) on aromatic compounds in wines were investigated. Using GC/FID-MS analysis, aroma compounds in Krstač and Žižak wines were characterized and quantified. Wines produced with the addition of yeast and yeast nutrients had mostly lower total alcohol content than wines obtained by spontaneous fermentation of Krstač and Žižak varieties. The results of this study showed that the concentration of compounds depends on the yeast strains. The yeast S. cerevisiae (ICV) provided a higher content of higher alcohols, while S. bayanus produced a higher concentration of esters and (medium chain) fatty acids. Total ester content ranged from 3.34 to 11.97 mg/l for Krstač wines and 8.51 to 13.68 mg/l for Žižak wines. Among all wines, Krstač and Žižak wines produced with S. bayanus and Fermaid E addition had the highest concentration of total esters. The yeast nutrients Fermaid E and O emphasized different characteristics of the yeasts. They had a statistically significant effect on the content of ethyl and acetate esters. The highest overall scores were obtained for ICVE and BayE Krstač wines (18.1 out of 20 points) and Žižak ICVE wine (18.2 out of 20 points).","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160206","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

The net peak splitting phenomenon in square-wave voltammetry – A simple diagnostic tool to distinguish between surface electrode mechanisms associated with different chemical reactions 方波伏安法中的净峰分裂现象--区分与不同化学反应相关的表面电极机制的简单诊断工具

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-12-24 DOI: 10.20450/mjcce.2023.2782

R. Gulaboski

{"title":"The net peak splitting phenomenon in square-wave voltammetry – A simple diagnostic tool to distinguish between surface electrode mechanisms associated with different chemical reactions","authors":"R. Gulaboski","doi":"10.20450/mjcce.2023.2782","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2782","url":null,"abstract":"Utilizing pulse voltammetric techniques for the electrochemical analysis of lipophilic redox systems has proven to be an effective method for studying a diverse range of redox compounds, from simple molecules to intricate proteins. To extract relevant thermodynamic and kinetic data from electrochemical analysis of redox systems exhibiting strong surface activity, there's a crucial need to decipher the underlying electrochemical mechanism in the system being examined. The \"split net peak\" phenomenon, a defining characteristic observed in all surface-active redox systems featuring fast electron transfer under square-wave voltammetry conditions, has been investigated in this study to establish diagnostic criteria for identifying surface electrochemical mechanisms associated with preceding, subsequent, regenerative, and reactant-inactivating chemical reactions. This understanding can be achieved by tracking the influence of the chemical reaction rate on the split square-wave voltammetric peaks in a particular electrochemical mechanism. The approach reported in the current work enables a very simple and precise differentiation between the elaborated mechanisms frequently encountered in protein-film voltammetry methodologies.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160778","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

Quantitative determination of hydroquinone via electrochemical methods at nano-architecture platinum electrode 纳米结构铂电极电化学法定量测定对苯二酚

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-29 DOI: 10.20450/mjcce.2023.2688

A. A Al-Owais, Ibrahim S El-Hallag, E. H. El-Mossalamy

引用次数: 0

Spectrofluorimetric determination of beta-blockers atenolol and bisoprolol fumarate residues in Senegal natural waters 用荧光光谱法测定塞内加尔天然水体中β受体阻滞剂阿替洛尔和富马酸比索洛尔的残留

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-27 DOI: 10.20450/mjcce.2023.2680

Coumba Gueye, P. A. Diaw, M. Mbaye, O. Mbaye, L. Cissé, Diabou Gaye Seye, J. Aaron, N. Oturan, M. Oturan

{"title":"Spectrofluorimetric determination of beta-blockers atenolol and bisoprolol fumarate residues in Senegal natural waters","authors":"Coumba Gueye, P. A. Diaw, M. Mbaye, O. Mbaye, L. Cissé, Diabou Gaye Seye, J. Aaron, N. Oturan, M. Oturan","doi":"10.20450/mjcce.2023.2680","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2680","url":null,"abstract":"A spectrofluorimetric method was developed to determine residues of two β-blockers, atenolol (AT) and bisoprolol fumarate (BF), in Senegal's natural waters. The electronic absorption and fluorescence spectral properties of both β-blockers were investigated in several organic solvent mixtures [e.g., MeOH/H2O (60/40 v/v), cyclodextrins (β-cyclodextrin, HP-β-CD], and in the presence of surfactants (SDS, Triton X, Tween 80). After optimization, satisfactory analytical figures of merit were obtained for the determination of both β-blockers: concentration linear dynamic range of over one to two orders of magnitude, limits of detection (LODs) from 1.3 to 5.4 ng/ml for BF and from 1.2 to 3.7 ng/ml for AT, limits of quantification (LOQs) from 4.5 to 18.1 ng/ml for BF and from 4.0 to 12.5 ng/ml for AT. Relative standard deviations (RSDs) were between 2.1 and 5.3 %, according to the β-blockers. The spectrofluorimetric method was applied to the analysis of fortified river water and wastewater (effluent) collected in Senegal and France and spiked with both β-blockers. It yielded good recovery values, from 93.3 to 107.8 % for AT and from 97.4 to 108.9 % for BF. Our results demonstrated the simplicity, rapidity, and sensitivity of the spectrofluorimetric method to quantify residues of β-blockers in environmental waters.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44817012","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

Polycyclic aromatic hydrocarbons in two sedimentary environments of the Tertiary Krepoljin coal basin 第三纪克雷波尔金煤盆地两种沉积环境中的多环芳烃

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-26 DOI: 10.20450/mjcce.2023.2552

G. Dević, M. Pergal, M. Pergal

{"title":"Polycyclic aromatic hydrocarbons in two sedimentary environments of the Tertiary Krepoljin coal basin","authors":"G. Dević, M. Pergal, M. Pergal","doi":"10.20450/mjcce.2023.2552","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2552","url":null,"abstract":"In the present study, statistical correlation analysis and multivariate statistical techniques (PCA/FA) were employed to investigate polycyclic aromatic hydrocarbons (PAHs) in sediments, such as illite-montmorillonite (IM) and calcite (Ct), from two sedimentary environments of the Tertiary Krepoljin brown coal basin in Serbia. The coal and sediment layers were formed in fresh-water bogs during the Lower Miocene period. The total amount of extractable PAHs was determined by gas chromatography with a triple quad mass detector (GC-MS-MS), and it ranged from 449 to 10585 μg l−1 in all sediments. Eight of the total 16 PAHs, which ranged from 175.17 to 658.42 μg l−1, include benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, which are regarded as potentially carcinogenic, indicating a higher possibility of adverse ecological effects. Medium molecular-weight (MMW) PAHs were found to be predominant in all sediments. PAH concentrations are affected by several factors, such as carbon content, H/C mole ratio, and (less significant) O/C mole ratio. The non-existence of a correlation between the N/C ratio and other parameters indicates unspecific changes which accompany the original organic matter. The lower-sulfur Ct sediment samples were found to have a higher PAH content than higher sulfur IM samples, leading to the conclusion that the PAH content of sediments may be related to the depositional environment.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42124140","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

Influence of electrodeposition regime and Sn:Pd ratios in Sn-Pd electrocatalysts on ethanol oxidation reaction Sn-Pd电催化剂中电沉积方式和Sn:Pd比对乙醇氧化反应的影响

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-26 DOI: 10.20450/mjcce.2023.2702

J. Lović, N. Nikolić, P. Živković, S. Dimitrijević, M. Stevanović

{"title":"Influence of electrodeposition regime and Sn:Pd ratios in Sn-Pd electrocatalysts on ethanol oxidation reaction","authors":"J. Lović, N. Nikolić, P. Živković, S. Dimitrijević, M. Stevanović","doi":"10.20450/mjcce.2023.2702","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2702","url":null,"abstract":"A series of bimetallic Sn-Pd catalysts were prepared by a template-free two step electrodeposition method. According to this method, Sn was electrodeposited firstly in potentiostatic or galvanostatic regime on Cu electrodes in the form of dendrites, then Pd was galvanostatically electrodeposited in the second step on the electrode with the electrodeposited Sn dendrites. The produced Sn-Pd electrocatalysts were compared with an electrocatalyst obtained by Pd electrodeposition on a bare Cu electrode. The morphological and elemental analysis of Sn-Pd and Pd electrocatalysts was performed by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The dendrites of various shapes and degree of branching were obtained by Sn deposition depending on electrodeposition regime, while Pd was electrodeposited in a form of compact Pd islands on both Sn dendrites and the Cu electrode. Cyclic voltammetry (CV) was applied for the electrochemical examination of Sn-Pd and Pd catalysts towards the ethanol oxidation reaction (EOR) in the alkaline solution. The electrocatalyst Sn0.6-Pd0.4 with an atomic ratio of 60 at.% Sn-40 at.% Pd showed higher oxidation efficiency and better tolerance towards intermediate species in EOR than the other examined electrocatalysts . It was shown that the lower fraction of Pd, relative to Sn, was crucial to achieving optimal synergy of Sn with Pd thus contributing to enhanced electrochemical behavior regarding EOR.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41274008","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

Development of a spectrophotometric method for assessment of the relative reactivity of monocarbonyl analogs of curcumin with 2-(dimethylamino)ethanethiol 姜黄素单羰基类似物与2-(二甲氨基)乙硫醇相对反应性的分光光度法研究

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-12 DOI: 10.20450/mjcce.2023.2638

Zlatko Lozanovski, J. Petreska Stanoeva, J. Bogdanov

{"title":"Development of a spectrophotometric method for assessment of the relative reactivity of monocarbonyl analogs of curcumin with 2-(dimethylamino)ethanethiol","authors":"Zlatko Lozanovski, J. Petreska Stanoeva, J. Bogdanov","doi":"10.20450/mjcce.2023.2638","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2638","url":null,"abstract":"In order to improve the bioavailability of curcumin, studies have been undertaken to prepare the so-called monocarbonyl analogs of curcumin (MACs) and assess their biological activity. These analogs contain an electrophilic α,β-unsaturated carbonyl moiety (Michael acceptor). Several key biological processes are connected/controlled with thiol alkylation (glutathione, cysteine, cysteine peptide residues). The most likely reaction is the Michael addition between the α,β-unsaturated acceptor and a corresponding thiol. 2,6-Bisarylidenecyclohexanone and 3,5-bisarylidenepiperidin-4-one scaffolds offer convenient tunability of electrophilicity and redox properties of the Michael acceptor by the introduction of various substituents. In this study, several MACs were prepared by Claisen-Schmidt condensation reaction, and their reactivity with 2-(dimethylamino)ethanethiol was evaluated. For this purpose, based on the UV-Vis spectra of the analogs and thiol(s), a proper method for spectrophotometric evaluation of their reactivity with 2-(dimethylamino)ethanethiol was optimized. The relative reactivity of the analogs was 7 > 2 > 5 > 4 > 1 ≈ 6. The developed method is simple, and it can be extended to assess the reactivity of other MACs.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46566713","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

Heptagonal quasicrystals: Construction of 2D lattices and demonstrations using laser pointers – Concluding part 七阶段准晶体：2D晶格的构建和使用激光指示器的演示——结束部分

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-06-12 DOI: 10.20450/mjcce.2023.2675

V. Petruševski, Sašo Kalajdžievski

引用次数: 0

Carbonic anhydrase inhibitory activities of novel proton transfer salts and their Cu(II) complexes 新型质子转移盐及其Cu（II）配合物对碳酸酐酶的抑制活性

IF 1 4区化学

Macedonian Journal of Chemistry and Chemical Engineering Pub Date : 2023-05-30 DOI: 10.20450/mjcce.2023.2563

H. İlkimen, Yasemin Tunca, Ekrem Tunca, M. Bülbül, C. Yeni̇kaya

{"title":"Carbonic anhydrase inhibitory activities of novel proton transfer salts and their Cu(II) complexes","authors":"H. İlkimen, Yasemin Tunca, Ekrem Tunca, M. Bülbül, C. Yeni̇kaya","doi":"10.20450/mjcce.2023.2563","DOIUrl":"https://doi.org/10.20450/mjcce.2023.2563","url":null,"abstract":"In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)– (1) and (ClHabt)+(pabsmal)– (2), were obtained from 2-amino-6-chlorobenzothiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoylphenyl)maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (1H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 µM and 4.25 ± 0.100 µM for hCA I, and of 0.02 ± 0.001 µM and 3.21 ± 0.200 µM for hCA II.","PeriodicalId":18088,"journal":{"name":"Macedonian Journal of Chemistry and Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48756614","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