Pub Date : 2022-08-07DOI: 10.6001/chemija.v33i3.4750
Anastasiia Belikova, Anna Materienko, Ludmila Sidorenko, Olha Chorna, Deividas Burdulis, V. Georgiyants
A method for the determination of amizone and amixin in the same sample and in their mixture with antibiotics (ceftriaxone, tetracycline, ampicillin and levofloxacin) was developed using reversed-phase highperformance liquid chromatography equipped with a photodiode array detector. A SunFire C18 column, a mobile phase consisting of sodium perchlorate buffer (pH = 2.5) and acetonitrile (75:25), at a flow rate of 0.8 ml/min, was used. The analytes were identified at 205 and 265 nm. The specificity, linearity, precision parameters, LOD and LOQ were evaluated during the validation of the methodology, and the correlation coefficients of amizone and amixin were 0.9992 and 0.9998, respectively. This method can also be used for the determination of amizone and amixin and their presence in a mixture with antibiotics in the environment.
{"title":"Development of a method for the detection of amixin and amizon by HPLC on SunFire C18 column","authors":"Anastasiia Belikova, Anna Materienko, Ludmila Sidorenko, Olha Chorna, Deividas Burdulis, V. Georgiyants","doi":"10.6001/chemija.v33i3.4750","DOIUrl":"https://doi.org/10.6001/chemija.v33i3.4750","url":null,"abstract":"A method for the determination of amizone and amixin in the same sample and in their mixture with antibiotics (ceftriaxone, tetracycline, ampicillin and levofloxacin) was developed using reversed-phase highperformance liquid chromatography equipped with a photodiode array detector. A SunFire C18 column, a mobile phase consisting of sodium perchlorate buffer (pH = 2.5) and acetonitrile (75:25), at a flow rate of 0.8 ml/min, was used. The analytes were identified at 205 and 265 nm. The specificity, linearity, precision parameters, LOD and LOQ were evaluated during the validation of the methodology, and the correlation coefficients of amizone and amixin were 0.9992 and 0.9998, respectively. This method can also be used for the determination of amizone and amixin and their presence in a mixture with antibiotics in the environment.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46645096","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}
Pub Date : 2022-08-07DOI: 10.6001/chemija.v33i3.4751
Adrián Vicent Claramunt, Audrius Sadaunykas, Birutė Knašienė, E. Naujalis
We aimed to demonstrate that breath analysis can be used as a method for the detection of potentially harmful compounds in food after their ingestion. Development of such a method could be adapted as a tool for detection of food intoxication. To achieve this, we compared the levels of pyridine (Py) and furfuryl alcohol (FFA) found in breath with the quantity of these compounds ingested when drinking coffee. Coffee drink beverages were prepared in the laboratory and consumed by volunteers (n = 5). An aliquot of coffee was analysed using high performance liquid chromatography with diode-array detection (HPLC-DAD) to quantify Py and FFA in the beverage. Breath samples were collected several times over a 45 min period after ingestion of coffee and analysed by thermal desorption coupled to gas chromatography/mass spectrometry (TD/GC-MS). The levels of Py and FFA found in coffee ranged from 0.2 to 3 mg/cup of coffee, and from 7 to 30 mg/cup of coffee, respectively. The levels of these compounds detected in breath ranged from 7 to 1200 ng/l breath for Py and from 1 to 760 ng/l breath for FFA. Several parameters can influence the levels of these chemicals in breath, especially the collection time of the breath sample.
{"title":"Determination of pyridine and furfuryl alcohol in breath after coffee consumption","authors":"Adrián Vicent Claramunt, Audrius Sadaunykas, Birutė Knašienė, E. Naujalis","doi":"10.6001/chemija.v33i3.4751","DOIUrl":"https://doi.org/10.6001/chemija.v33i3.4751","url":null,"abstract":"We aimed to demonstrate that breath analysis can be used as a method for the detection of potentially harmful compounds in food after their ingestion. Development of such a method could be adapted as a tool for detection of food intoxication. To achieve this, we compared the levels of pyridine (Py) and furfuryl alcohol (FFA) found in breath with the quantity of these compounds ingested when drinking coffee. Coffee drink beverages were prepared in the laboratory and consumed by volunteers (n = 5). An aliquot of coffee was analysed using high performance liquid chromatography with diode-array detection (HPLC-DAD) to quantify Py and FFA in the beverage. Breath samples were collected several times over a 45 min period after ingestion of coffee and analysed by thermal desorption coupled to gas chromatography/mass spectrometry (TD/GC-MS). The levels of Py and FFA found in coffee ranged from 0.2 to 3 mg/cup of coffee, and from 7 to 30 mg/cup of coffee, respectively. The levels of these compounds detected in breath ranged from 7 to 1200 ng/l breath for Py and from 1 to 760 ng/l breath for FFA. Several parameters can influence the levels of these chemicals in breath, especially the collection time of the breath sample.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44949454","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}
Pub Date : 2022-08-07DOI: 10.6001/chemija.v33i3.4748
G. Bikulčius, S. Lichušina, V. Pakštas, M. Gedvilas, V. Stankevič, A. Selskienė, A. Grigucevičienė
In this article, we have introduced a new method that can improve the corrosion resistance of AZ31 alloy. We compared the biodegradation of AZ31 alloy foil treated with a high current density impulse (HCDI), laser irradiation (LI) and HCDI-LI with that of the untreated one. The rate of the biodegradation of AZ31 alloy treated with HCDI-LI was lower than those of the untreated one, the alloy treated with HCDI or LI. Thus, the improved corrosion resistance of the AZ31 alloy treated with HCDI-LI allows its use for medical purposes.
{"title":"Corrosion resistance of AZ31 alloy after treatment with high current density impulse or/and laser irradiation in Hank’s solution","authors":"G. Bikulčius, S. Lichušina, V. Pakštas, M. Gedvilas, V. Stankevič, A. Selskienė, A. Grigucevičienė","doi":"10.6001/chemija.v33i3.4748","DOIUrl":"https://doi.org/10.6001/chemija.v33i3.4748","url":null,"abstract":"In this article, we have introduced a new method that can improve the corrosion resistance of AZ31 alloy. We compared the biodegradation of AZ31 alloy foil treated with a high current density impulse (HCDI), laser irradiation (LI) and HCDI-LI with that of the untreated one. The rate of the biodegradation of AZ31 alloy treated with HCDI-LI was lower than those of the untreated one, the alloy treated with HCDI or LI. Thus, the improved corrosion resistance of the AZ31 alloy treated with HCDI-LI allows its use for medical purposes.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43481445","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}
Pub Date : 2022-05-04DOI: 10.6001/chemija.v33i2.4706
Mamdouh Alasabashi, A. Ževžikovienė, M. Marksa, Laura Rimkiene, A. Ževžikovas
It was established that self-poisoning with antipsychotics, anti-anxiety drugs and antidepressants is caused by consumption of the drug in higher doses than prescribed. So it is very important to determine fast the materials causing poisoning and use the method which would allow one to identify several substances during only one analysis. Reference and test solutions were prepared in ethanol. A qualitative and quantitative analysis was carried out on a Waters Alliance 2695 liquid chromatograph equipped with a Waters 996 PDA detector and an ACE C18 (250 mm × 4.6 mm × 5 μm) column. The mobile phase consisted of solvent trifluoroacetic acid (0.1 %) and acetonitrile. The linear gradient elution profile was used. For the validation process the following parameters were chosen: specificity, repeatability, precision and limits (LOD and LOQ). According to the study results, it can be concluded that the validated method for the qualitative and quantitative evaluation analysis of olanzapine, clorazepate and escitalopram was developed.
已经确定的是，服用抗精神病药物、抗焦虑药物和抗抑郁药物的自我中毒是由于服用剂量高于处方剂量造成的。因此，快速确定引起中毒的物质和使用在一次分析中可以识别多种物质的方法是非常重要的。在乙醇中制备参比液和被试液。采用Waters Alliance 2695型液相色谱仪，配备Waters 996 PDA检测器和ACE C18 (250 mm × 4.6 mm × 5 μm)色谱柱进行定性和定量分析。流动相为溶剂三氟乙酸(0.1%)和乙腈。采用线性梯度洗脱剖面。对于验证过程，选择以下参数:特异性、重复性、精密度和限(LOD和LOQ)。根据研究结果，建立了奥氮平、氯硝西酯和艾司西酞普兰的定性和定量评价分析方法。
{"title":"The validated method for the analysis of a mixture of psychotropic medicines olanzapine, clorazepate and escitalopram using a high-performance liquid chromatography method","authors":"Mamdouh Alasabashi, A. Ževžikovienė, M. Marksa, Laura Rimkiene, A. Ževžikovas","doi":"10.6001/chemija.v33i2.4706","DOIUrl":"https://doi.org/10.6001/chemija.v33i2.4706","url":null,"abstract":"It was established that self-poisoning with antipsychotics, anti-anxiety drugs and antidepressants is caused by consumption of the drug in higher doses than prescribed. So it is very important to determine fast the materials causing poisoning and use the method which would allow one to identify several substances during only one analysis. Reference and test solutions were prepared in ethanol. A qualitative and quantitative analysis was carried out on a Waters Alliance 2695 liquid chromatograph equipped with a Waters 996 PDA detector and an ACE C18 (250 mm × 4.6 mm × 5 μm) column. The mobile phase consisted of solvent trifluoroacetic acid (0.1 %) and acetonitrile. The linear gradient elution profile was used. For the validation process the following parameters were chosen: specificity, repeatability, precision and limits (LOD and LOQ). According to the study results, it can be concluded that the validated method for the qualitative and quantitative evaluation analysis of olanzapine, clorazepate and escitalopram was developed.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44188926","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}
Pub Date : 2022-05-04DOI: 10.6001/chemija.v33i2.4708
V. Jakubkienė, Mantas Žvirblis, S. Tumkevičius
The histone deacetylases (HDACs) play an essential role in the transcriptional regulation of cells through deacetylation of nuclear histone proteins and are promising therapeutic targets for treatment of various diseases. Therefore, interest to the design and synthesis of novel HDAC inhibitors, among which hydroxamic acids occupy an important place, has been constantly increasing in recent years. Here, synthesis of pyrimidines with 1,3,4-oxadiazole or 1,2,4-triazole and hydroxamic acid moieties as potential HDAC inhibitors is described. The target compounds were obtained by sequential reactions of (O- and N-pyrimidinyl)alkanoates with hydrazine hydrate followed by cyclization reaction of the obtained hydrazides with potassium O-ethyl xanthate and alkylation of the synthesised oxadiazole(triazole)thiones with 2-chloro-N-hydroxyacetamide. One of 1,3,4-oxadiazole-2-thiones under the treatment with hydrazine hydrate underwent the recyclisation reaction to give the corresponding 4-amino-1,2,4-triazole. Investigation of the inhibitory activity of the synthesised compounds against HDAC4 and HDAC8 isoforms revealed that N-hydroxy-2-(5-(4-(6-(6-methyl-2-(methylthio)pyrimidin-4-yloxy) butyl)-1,3,4-oxadiazol-2-ylthio)acetamide exhibited a weak inhibitory activity against HDAC8 isoform (IC50 = 12.7 μM).
{"title":"Synthesis of pyrimidines containing hydroxamic acid, 1,3,4-oxadiazole or 1,2,4-triazole moieties as potential HDAC inhibitors","authors":"V. Jakubkienė, Mantas Žvirblis, S. Tumkevičius","doi":"10.6001/chemija.v33i2.4708","DOIUrl":"https://doi.org/10.6001/chemija.v33i2.4708","url":null,"abstract":"The histone deacetylases (HDACs) play an essential role in the transcriptional regulation of cells through deacetylation of nuclear histone proteins and are promising therapeutic targets for treatment of various diseases. Therefore, interest to the design and synthesis of novel HDAC inhibitors, among which hydroxamic acids occupy an important place, has been constantly increasing in recent years. Here, synthesis of pyrimidines with 1,3,4-oxadiazole or 1,2,4-triazole and hydroxamic acid moieties as potential HDAC inhibitors is described. The target compounds were obtained by sequential reactions of (O- and N-pyrimidinyl)alkanoates with hydrazine hydrate followed by cyclization reaction of the obtained hydrazides with potassium O-ethyl xanthate and alkylation of the synthesised oxadiazole(triazole)thiones with 2-chloro-N-hydroxyacetamide. One of 1,3,4-oxadiazole-2-thiones under the treatment with hydrazine hydrate underwent the recyclisation reaction to give the corresponding 4-amino-1,2,4-triazole. Investigation of the inhibitory activity of the synthesised compounds against HDAC4 and HDAC8 isoforms revealed that N-hydroxy-2-(5-(4-(6-(6-methyl-2-(methylthio)pyrimidin-4-yloxy) butyl)-1,3,4-oxadiazol-2-ylthio)acetamide exhibited a weak inhibitory activity against HDAC8 isoform (IC50 = 12.7 μM).","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46266601","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}
Pub Date : 2022-05-04DOI: 10.6001/chemija.v33i2.4707
Lina Misevičienė, K. Krikštopaitis, N. Čėnas
We compared the redox properties of recombinant cytosolic (TrxR1) and mitochondrial (TrxR2) isoforms of human flavosulfoselenoenzyme NADPH:thioredoxin reductase. The standard redox potentials of isoenzymes (E0 7), determined according to the redox equilibrium with the NADP+/NADPH couple, were equal to –0.295 V (TrxR1) and –0.270 V (TrxR2). The more positive value of E0 7 of TrxR2 may be attributed to the presence of His-125 at the vicinity of catalytic disulfide and selenylsulfide, instead of Tyr-116 in TrxR1. The reactivity of several quinones and nitroaromatic compounds towards TrxR1 and TrxR2 increased with their single-electron reduction potential (E1 7). For the first time, we studied the TrxR1-catalysed reduction of a series of aromatic N-oxides which were reduced in a mixed single- and two-electron way. Their reactivity was close to that of quinones and nitroaromatics with the similar values of E1 7.
我们比较了重组人黄磺基硒酶NADPH:硫氧还蛋白还原酶的细胞质(TrxR1)和线粒体(TrxR2)异构体的氧化还原特性。根据NADP+/NADPH对氧化还原平衡测定的同工酶(e07)的标准氧化还原电位分别为-0.295 V (TrxR1)和-0.270 V (TrxR2)。TrxR2的e07较高的正值可能是由于His-125存在于催化二硫化物和硒基硫化物附近，而不是TrxR1中的tyrl -116。几种醌类和硝基芳香化合物对TrxR1和TrxR2的反应活性随着其单电子还原电位的增加而增加(E1 7)。我们首次研究了TrxR1催化的一系列芳香n -氧化物的单电子和双电子混合还原。它们的反应活性接近醌类和硝基芳烃类，E1 - 7值相近。
{"title":"The comparative study of redox properties of recombinant human cytosolic and mitochondrial NADPH: thioredoxin reductases","authors":"Lina Misevičienė, K. Krikštopaitis, N. Čėnas","doi":"10.6001/chemija.v33i2.4707","DOIUrl":"https://doi.org/10.6001/chemija.v33i2.4707","url":null,"abstract":"We compared the redox properties of recombinant cytosolic (TrxR1) and mitochondrial (TrxR2) isoforms of human flavosulfoselenoenzyme NADPH:thioredoxin reductase. The standard redox potentials of isoenzymes (E0 7), determined according to the redox equilibrium with the NADP+/NADPH couple, were equal to –0.295 V (TrxR1) and –0.270 V (TrxR2). The more positive value of E0 7 of TrxR2 may be attributed to the presence of His-125 at the vicinity of catalytic disulfide and selenylsulfide, instead of Tyr-116 in TrxR1. The reactivity of several quinones and nitroaromatic compounds towards TrxR1 and TrxR2 increased with their single-electron reduction potential (E1 7). For the first time, we studied the TrxR1-catalysed reduction of a series of aromatic N-oxides which were reduced in a mixed single- and two-electron way. Their reactivity was close to that of quinones and nitroaromatics with the similar values of E1 7.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43432082","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}
Pub Date : 2022-05-04DOI: 10.6001/chemija.v33i2.4709
J. Jonikaitė-Švėgždienė, Liepa Pastarnokienė, Virginija Juknevičiūtė, R. Makuška
In this study, curing of BPA-based epoxy resins Araldite®GY-2600 and Araldite®GY-240 by low-molecular-weight amines EDA, TETA and Jeffamine D-230, and bio-based phenalkamines Cardolite®NX-6019, Cardolite®Lite-2002 and Cardolite®GX-6004 was studied by differential scanning calorimetry (DSC) and rheology measurements. DSC provided quantitative information on the overall reaction kinetics (the enthalpy of curing reaction, ΔHR; cure degree, α; curing reaction rate, dα/dt) and the glass transition temperature (Tg) of the cured product. It was demonstrated that the DSC curing of epoxy resins by phenalkamines started at lower temperature, and the curing rates were slightly lower compared to those cured by low-molecular-weight amine hardeners. The enthalpy of the curing by phenalkamines was lower, especially in the case of more viscous epoxy resin GY-2600. Tg of the cured epoxy resins varied from 50 to 98°C and was slightly lower when cured with cardanol-based phenalkamines. The results demonstrate that curing of epoxy resins by bio-based phenalkamines proceeds in a similar temperature interval like using low-molecular-weight amines as hardeners but with less exothermic effect, which could be an advantage.
{"title":"Curing of epoxy resins by bio-based phenalkamines vs low-molecular-weight amines: study by DSC","authors":"J. Jonikaitė-Švėgždienė, Liepa Pastarnokienė, Virginija Juknevičiūtė, R. Makuška","doi":"10.6001/chemija.v33i2.4709","DOIUrl":"https://doi.org/10.6001/chemija.v33i2.4709","url":null,"abstract":"In this study, curing of BPA-based epoxy resins Araldite®GY-2600 and Araldite®GY-240 by low-molecular-weight amines EDA, TETA and Jeffamine D-230, and bio-based phenalkamines Cardolite®NX-6019, Cardolite®Lite-2002 and Cardolite®GX-6004 was studied by differential scanning calorimetry (DSC) and rheology measurements. DSC provided quantitative information on the overall reaction kinetics (the enthalpy of curing reaction, ΔHR; cure degree, α; curing reaction rate, dα/dt) and the glass transition temperature (Tg) of the cured product. It was demonstrated that the DSC curing of epoxy resins by phenalkamines started at lower temperature, and the curing rates were slightly lower compared to those cured by low-molecular-weight amine hardeners. The enthalpy of the curing by phenalkamines was lower, especially in the case of more viscous epoxy resin GY-2600. Tg of the cured epoxy resins varied from 50 to 98°C and was slightly lower when cured with cardanol-based phenalkamines. The results demonstrate that curing of epoxy resins by bio-based phenalkamines proceeds in a similar temperature interval like using low-molecular-weight amines as hardeners but with less exothermic effect, which could be an advantage.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48926200","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}
Pub Date : 2022-05-04DOI: 10.6001/chemija.v33i2.4705
Rasa Karalkevičienė, Greta Briedytė, T. Murauskas, Mantas Norkus, A. Zarkov, J. Yang, A. Kareiva
The wet chemistry route has been developed to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, (HA)) thin films on a silicon substrate using the novel low-temperature sol-gel and dissolution-precipitation approach. The calcium carbonate thin films on the silicon substrate were obtained by spin-coating technique when substrates were repeatedly coated with 10, 20 and 30 layers of sol-gel solution. The composites formed of crystalline and amorphous CaCO3 were obtained by calcination of the coatings for different time at 600°C. A dissolution-precipitation procedure was used for the preparation of calcium hydroxyapatite thin films on silicon substrate at 80°C. The obtained synthesis products were characterised by X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) and Raman spectroscopy.
{"title":"A novel method for the formation of bioceramic nano-calcium hydroxyapatite coatings using sol-gel and dissolution-precipitation processing","authors":"Rasa Karalkevičienė, Greta Briedytė, T. Murauskas, Mantas Norkus, A. Zarkov, J. Yang, A. Kareiva","doi":"10.6001/chemija.v33i2.4705","DOIUrl":"https://doi.org/10.6001/chemija.v33i2.4705","url":null,"abstract":"The wet chemistry route has been developed to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, (HA)) thin films on a silicon substrate using the novel low-temperature sol-gel and dissolution-precipitation approach. The calcium carbonate thin films on the silicon substrate were obtained by spin-coating technique when substrates were repeatedly coated with 10, 20 and 30 layers of sol-gel solution. The composites formed of crystalline and amorphous CaCO3 were obtained by calcination of the coatings for different time at 600°C. A dissolution-precipitation procedure was used for the preparation of calcium hydroxyapatite thin films on silicon substrate at 80°C. The obtained synthesis products were characterised by X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) and Raman spectroscopy.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47359774","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}
Pub Date : 2022-02-07DOI: 10.6001/chemija.v33i1.4661
A. V. Claramunt, Audrius Sadaunykas, Simonas Balčiūnas, Birutė Knašienė, Audrius Zolumskis, E. Naujalis
The aim of this study was to show how volatile organic compounds (VOCs) profiling can be used as a method to identify different environments across a city. To achieve that, we employed several methods. First, we carried out the profiling of VOCs in several different locations. Then we identified the marker compounds and their sources. Air samples were collected from 6 different locations within the Vilnius City centre using thermal desorption (TD) tubes. Samples were analysed using thermal desorption coupled with gas chromatography mass spectroscopy (TD/GC-MS) methodology. Compound identification was performed by the library match using the NIST MS Search 2.0 (2005) mass spectral library. The results show how variation in the levels of different VOCs can distinguish between locations within a relatively small area of 2 km2 depending on different emission sources.
这项研究的目的是展示挥发性有机化合物(VOCs)分析如何被用作识别城市不同环境的方法。为了达到这个目的，我们采用了几种方法。首先，我们对几个不同地点的VOCs进行了分析。然后我们确定了标记化合物及其来源。使用热解吸(TD)管从维尔纽斯市中心的6个不同地点收集空气样本。采用热解吸-气相色谱-质谱联用(TD/GC-MS)方法对样品进行分析。化合物鉴定采用NIST MS Search 2.0(2005)质谱库匹配。结果表明，不同挥发性有机化合物水平的变化如何根据不同的排放源在相对较小的2平方公里范围内区分不同地点。
{"title":"Profiling of volatile organic compounds for environment discrimination in Vilnius City","authors":"A. V. Claramunt, Audrius Sadaunykas, Simonas Balčiūnas, Birutė Knašienė, Audrius Zolumskis, E. Naujalis","doi":"10.6001/chemija.v33i1.4661","DOIUrl":"https://doi.org/10.6001/chemija.v33i1.4661","url":null,"abstract":"The aim of this study was to show how volatile organic compounds (VOCs) profiling can be used as a method to identify different environments across a city. To achieve that, we employed several methods. First, we carried out the profiling of VOCs in several different locations. Then we identified the marker compounds and their sources. Air samples were collected from 6 different locations within the Vilnius City centre using thermal desorption (TD) tubes. Samples were analysed using thermal desorption coupled with gas chromatography mass spectroscopy (TD/GC-MS) methodology. Compound identification was performed by the library match using the NIST MS Search 2.0 (2005) mass spectral library. The results show how variation in the levels of different VOCs can distinguish between locations within a relatively small area of 2 km2 depending on different emission sources.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46211880","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}
Pub Date : 2022-02-07DOI: 10.6001/chemija.v33i1.4657
Edita Daublytė, Agnė Zdaniauskienė, T. Charkova
The silver nanospheres (70 ± 5 nm) were synthesised and decorated with silica under microwave irradiation. The obtained silver core-silica decorated nanoparticles (80 ± 5 nm) were applied for 4-mercaptobenzoic acid monolayer analysis by shell-isolated nanoparticle-enhanced Raman spectroscopy. A detailed protocol of synthesis, characterisation by UV/Vis, HR-TEM and Raman techniques are represented here.
{"title":"Microwave synthesis of silver core-silica decorated nanoparticles","authors":"Edita Daublytė, Agnė Zdaniauskienė, T. Charkova","doi":"10.6001/chemija.v33i1.4657","DOIUrl":"https://doi.org/10.6001/chemija.v33i1.4657","url":null,"abstract":"The silver nanospheres (70 ± 5 nm) were synthesised and decorated with silica under microwave irradiation. The obtained silver core-silica decorated nanoparticles (80 ± 5 nm) were applied for 4-mercaptobenzoic acid monolayer analysis by shell-isolated nanoparticle-enhanced Raman spectroscopy. A detailed protocol of synthesis, characterisation by UV/Vis, HR-TEM and Raman techniques are represented here.","PeriodicalId":9720,"journal":{"name":"Chemija","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47139767","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：