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Switchable hydrophilicity solvent-based hollow fibre liquid-liquid microextraction – headspace gas chromatography for determination of benzene and its derivatives in water samples 基于可切换亲水性溶剂的中空纤维液-液微萃取-顶空气相色谱法测定水样中的苯及其衍生物

IF 0.6 4区化学

Chemija Pub Date : 2024-04-03 DOI: 10.6001/chemija.2024.35.1.3

V. Vickackaite, Vasarė Viselgaitė, Vilius Poškus

{"title":"Switchable hydrophilicity solvent-based hollow fibre liquid-liquid microextraction – headspace gas chromatography for determination of benzene and its derivatives in water samples","authors":"V. Vickackaite, Vasarė Viselgaitė, Vilius Poškus","doi":"10.6001/chemija.2024.35.1.3","DOIUrl":"https://doi.org/10.6001/chemija.2024.35.1.3","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000A novel, cost-effective, simple and environmentally friendly method was developed for separating, preconcentrating and quantifying volatile analytes. That approach utilised switchable hydrophilicity solvent-based hollow fiber liquid-liquid microextraction in combination with headspace gas chromatography. The extraction was carried out from 1 l of water solution. 100 μl of nonanoic acid, immobilised within a polypropylene capillary, was selected as an extraction solvent. After the extraction, the capillary with the extract was transferred to a headspace vial, and headspace gas chromatographic analysis was performed. To facilitate the transition of volatile analytes to the headspace for subsequent analysis, nonanoic acid was converted to hydrophilic nonanoate by adding a sodium hydroxide solution. \u0000The effectiveness of the suggested strategy was demonstrated in the determination of benzene and its derivatives in water samples. Various parameters affecting the extraction and headspace gas chromatographic determination were investigated and optimised. Under the optimal conditions, the analytical characteristics of the proposed technique were determined. \u0000Using this approach, the limits of quantification for all analytes were found to be below the maximum acceptable concentration. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140748708","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 influence of raw material preparation on the yield of bioactive substances in lingonberry (Vaccinium vitis-idaea L.) fruits 原料制备对越橘（Vaccinium vitis-idaea L.）果实中生物活性物质产量的影响

IF 0.6 4区化学

Chemija Pub Date : 2024-04-03 DOI: 10.6001/chemija.2024.35.1.1

J. Daukšienė, Kristina Burdulienė, Gediminas Daukšys, Lauryna Paulauskaitė, Deividas Burdulis

引用次数: 0

Aqueous two-phase system based on hexafluoroisopropanol and acetonitrile for homogeneous liquid-liquid microextraction of cationic dyes 基于六氟异丙醇和乙腈的水基两相系统用于阳离子染料的均相液-液微萃取

IF 0.6 4区化学

Chemija Pub Date : 2024-04-03 DOI: 10.6001/chemija.2024.35.1.2

Vytautas Kavaliauskas, A. Padarauskas

{"title":"Aqueous two-phase system based on hexafluoroisopropanol and acetonitrile for homogeneous liquid-liquid microextraction of cationic dyes","authors":"Vytautas Kavaliauskas, A. Padarauskas","doi":"10.6001/chemija.2024.35.1.2","DOIUrl":"https://doi.org/10.6001/chemija.2024.35.1.2","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000This work demonstrates that an aqueous two-phase system (ATPS) is formed when a small amount of acetonitrile (ACN) is added to the aqueous hexafluoroisopropanol (HFIP) solution. The effect of ACN amount on the volume of the formed HFIP/ACN phase was investigated. It was also shown that relatively hydrophilic methylene blue was completely extracted into the HFIP/ACN phase whereas its extractability with conventional solvents (hexane, CH2Cl2 and CHCl3) was significantly lower. The obtained results suggest that the HFIP/ACN phase exhibits a relatively high polarity and should be a good choice for the extraction of moderately or even highly polar compounds from aqueous samples. Finally, the developed ATPS was applied for the homogeneous liquidliquid microextraction of four cationic dyes from river water samples prior to HPLC analysis. Under optimised extraction conditions, the enrichment factors were around 150. Calibration curves were linear (R2 ≥ 0.9959) for the concentration level between 0.2–0.5 and 50.0 μg/L and the detection limits were in the range 0.05–0.18 μg/L. The recoveries of the dyes for the spiked water samples were 88.6–98.5%, with the relative standard deviation values less than 9.6%. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140748321","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

Synthesis and investigation of antibacterial activity of 1-(4-substituted phenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives 1-(4-取代苯基)-5-氧代吡咯烷-3-甲酰肼衍生物的合成及其抗菌活性研究

IF 0.6 4区化学

Chemija Pub Date : 2023-12-07 DOI: 10.6001/chemija.2023.34.4.3

Aurimas Plaga, Birutė Sapijanskaitė-Banevič, R. Vaickelionienė

{"title":"Synthesis and investigation of antibacterial activity of 1-(4-substituted phenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives","authors":"Aurimas Plaga, Birutė Sapijanskaitė-Banevič, R. Vaickelionienė","doi":"10.6001/chemija.2023.34.4.3","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.4.3","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000Hydrazides are very important precursors for the synthesis of a wide variety of derivatives, including heterocyclic compounds of biological interest in drug design and discovery. Acid hydrazides with a pyrrole, thiophene, furan, quinoline, isoquinoline, isoxazole and benzimidazole core in the structure were found to be used in medicine, pharmacy, agriculture and many other fields. \u0000In the search for compounds with antibacterial properties, mono- and dihydrazides were used in this study to prepare 1-(4-substituted phenyl)-5-oxopyr-rolidine-3-carbohydrazide derivatives bearing the corresponding hydrazone and azole substituents. \u0000The formation of the target compounds was performed via condensation reactions with the chosen aromatic aldehydes and isatin, which led to the construction of the appropriate hydrazone-type structures as well as with diketones which afforded compounds with pyrazole and pyrrole nuclei. \u0000In addition, a preliminary antibacterial evaluation of the synthesised compounds was performed using the gram-positive Bacillus subtilis and the gramnegative Escherichia coli bacterial strains. As it was expected, the evaluation revealed potential antibacterial candidates that can help address the global challenges of antibiotic resistance and infectious disease outbreaks. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138983580","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

Synthesis of novel 4-alkyl-6-(5-aryl-1,2,3-thiadiazol-4-yl) benzene-1,3-diols as potential Hsp90 inhibitors 合成新型 4-烷基-6-（5-芳基-1,2,3-噻二唑-4-基）苯-1,3-二醇作为潜在的 Hsp90 抑制剂

IF 0.6 4区化学

Chemija Pub Date : 2023-12-07 DOI: 10.6001/chemija.2023.34.4.2

Paulina Kaziukonytė, Tomas Venslauskas, Kamilė Venskūnaitė, Ieva Žutautė, A. Brukštus

引用次数: 0

Hydrogen production on CoFe, CoFeMn and CoFeMo coatings deposited on Ni foam via electroless metal plating 通过无电解金属电镀沉积在泡沫镍上的 CoFe、CoFeMn 和 CoFeMo 涂层的制氢能力

IF 0.6 4区化学

Chemija Pub Date : 2023-12-07 DOI: 10.6001/chemija.2023.34.4.1

Huma Amber, Karina Vjūnova, Z. Sukackienė, D. Šimkūnaitė, J. Vaičiūnienė, L. Tamašauskaitė-Tamašiūnaitė, E. Norkus

{"title":"Hydrogen production on CoFe, CoFeMn and CoFeMo coatings deposited on Ni foam via electroless metal plating","authors":"Huma Amber, Karina Vjūnova, Z. Sukackienė, D. Šimkūnaitė, J. Vaičiūnienė, L. Tamašauskaitė-Tamašiūnaitė, E. Norkus","doi":"10.6001/chemija.2023.34.4.1","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.4.1","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000In this study, the catalytic hydrogen generation was evaluated on the cobalt–iron (CoFe), cobalt–iron–manganese (CoFeMn) and cobalt–ironmolybdenum (CoFeMo) coatings deposited on the Ni foam substrate using the electroless metal plating method and morpholine borane as the reducing agent. The characterisation of the surface morphology, structure and composition of resulted coatings was done using scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The catalytic activity of the prepared CoFe/Ni, CoFeMn/Ni and CoFeMo/Ni catalysts was investigated for hydrogen generation from an alkaline sodium borohydride (NaBH4) solution at different temperatures. It was found that the hydrogen generation rate of ca. 5.2, 7.8 and 11.7 L min–1 g–1 was achieved by using the CoFe/ Ni, CoFeMo/Ni and CoFeMn/Ni coatings, respectively, at 343 K. Among the investigated catalysts, CoFeMn/Ni exhibits the lowest activation energy of 62.4 kJ mol–1 and the highest HGR of 11.7 L min–1 g–1 at 343 K. \u0000 \u0000 \u0000 \u0000","PeriodicalId":9720,"journal":{"name":"Chemija","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011656","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

Synthesis of silver nanoparticles with polyols under reflux and microwave irradiation conditions 多元醇在回流和微波辐照条件下合成纳米银

4区化学

Chemija Pub Date : 2023-09-17 DOI: 10.6001/chemija.2023.34.3.1

Edita Daublytė, Marija Kalnaitytė, Aliona Klimovich, Audrius Drabavičius, Tatjana Charkova

引用次数: 0

Intrinsic emissions and formation of electron-hole trapping centres in excited Li2SO4 激发态Li2SO4的本征发射和电子空穴俘获中心的形成

4区化学

Chemija Pub Date : 2023-09-17 DOI: 10.6001/chemija.2023.34.3.2

Turlybek N. Nurakhmetov, Temirulan T. Alibay, Doszhan A. Tolekov, Raushan K. Shamiyeva, Sapargali Pazylbek, Dovydas Karoblis, Rimantas Raudonis, Aleksej Zarkov, Jonas Kiuberis, Aivaras Kareiva

引用次数: 0

Assessment of the deterioration process of copper alloys: a case study of Central Lithuanian crossbow brooches with a triangular foot 铜合金变质过程的评估:以立陶宛中部带三角形脚的十字弓胸针为例

4区化学

Chemija Pub Date : 2023-09-17 DOI: 10.6001/chemija.2023.34.3.3

Asta Vasiliauskaitė

引用次数: 0

Synthesis and dihydrofolate reductase inhibitory activity of 2-amino-6-(arylaminomethyl) thieno[2,3-d]pyrimidin-4(3H)-ones 2-氨基-6-(芳基氨基甲基)噻吩[2,3-d]嘧啶-4(3H)-酮的合成及二氢叶酸还原酶抑制活性

4区化学

Chemija Pub Date : 2023-09-17 DOI: 10.6001/chemija.2023.34.3.4

Mindaugas Dailidė, Sigitas Tumkevičius

{"title":"Synthesis and dihydrofolate reductase inhibitory activity of 2-amino-6-(arylaminomethyl) thieno[2,3-d]pyrimidin-4(3H)-ones","authors":"Mindaugas Dailidė, Sigitas Tumkevičius","doi":"10.6001/chemija.2023.34.3.4","DOIUrl":"https://doi.org/10.6001/chemija.2023.34.3.4","url":null,"abstract":"The present work deals with synthesis and biological evaluation of novel compounds as potential inhibitors of dihydrofolate reductase (DHFR) from opportunistic microorganisms – Pneumocystis carinii (pc), Toxoplasma gondii (tg) and Mycobacterium avium (ma). A set of 6 lipophilic and 1 classical antifolates of thieno[2,3-d]pyrimidine series were designed and synthesised with key pharmacophoric features of DHFR inhibitors and aminomethylene bridge joining the aromatic part and 2-amino-4-oxothieno[2,3-d]pyrimidine nucleus. Investigation of the DHFR inhibitory activity of the synthesised compounds revealed that 2-amino-6-[(4-methoxyphenylamino)-, 6--[(4-chlorophenylamino)- and 6-[(2,5 ichlorophenylamino)methyl]thieno[2,3-d]pyrimidin-4(3H)- ones had a moderate activity (IC50 56.5, 49.9 and 23 μM, respectively) against pcDHFR. Activity of those compounds against tgDHFR (IC50 6.0, 2.8 and 2.3 μM, respectively) was comparable to that of trimethoprim (IC50 2.7 μM). No synthesised lipophilic antifolates showed activity towards maDHFR. The classical antifolate 2-{4-[(2-amino-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidin-6-yl)methylamino]benzamido}-L-glutamic acid inhibited DHFRs from all microorganisms (IC50 6.6 μM for pcDHFR, 1.06 μM for tgDHFR and 16.9 μM for maDHFR).","PeriodicalId":9720,"journal":{"name":"Chemija","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259096","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