Pub Date : 2019-01-01DOI: 10.17721/moca.2019.153-162
O. Lukianova, A. Chebotarev, D. Snigur
Mixtures containing tartrazine (TAN) and brilliant blue (BB) or patented blue (PB) were investigated in this work. The optimal pH for the simultaneous determination of these dyes is 1.5 and 7 (for pH=7: ε430(ТАN)=3.2·104, ε635(ТАN)=5.3·102, ε430(PB)=3.3·103, ε635(PB)=8.7·104; for pH=1.5: ε430(ТАN)=2.1·104, ε630(ТАN)=9.6·102, ε430(BB)=9.3·103, ε630(BB)=8.3·104). Classification models, that allow to identify mixtures containing TAN and BB, TAN and PB, chlorophyll and quinoline yellow with BB or PB, have been developed using methods of hierarchical cluster analysis, factor analysis (FA), partial least squares (PLS) and principal component analysis (PCA). Model solutions of dyes and 12 real objects (tarkhun, low-alcohol drinks, tonics and absinthe of various brands) were used for the classification. The best classification results were achieved at pH 1.5 using PLS and PCA. Quantitative models, based on the additivity of spectral signals and PLS, have been developed for determining the permittivity of these dyes in the simultaneous presence. In order to make it possible to analyse alcoholic drinks, the dependence of the molar attenuation coefficient on the dielectric conductivity of solvents was studied. The obtained regression equations were taken into account in the calibration for absorbance additivity. Methods for the quantitative determination of the investigated dyes were developed for the concentration range 0.2-2.0∙10-5 М.
{"title":"Simultaneous Determination Of Tartrazine, Patented Blue V And Brilliant Blue FCF By Spectrophotometry With Chemometric Algorithms","authors":"O. Lukianova, A. Chebotarev, D. Snigur","doi":"10.17721/moca.2019.153-162","DOIUrl":"https://doi.org/10.17721/moca.2019.153-162","url":null,"abstract":"Mixtures containing tartrazine (TAN) and brilliant blue (BB) or patented blue (PB) were investigated in this work. The optimal pH for the simultaneous determination of these dyes is 1.5 and 7 (for pH=7: ε430(ТАN)=3.2·104, ε635(ТАN)=5.3·102, ε430(PB)=3.3·103, ε635(PB)=8.7·104; for pH=1.5: ε430(ТАN)=2.1·104, ε630(ТАN)=9.6·102, ε430(BB)=9.3·103, ε630(BB)=8.3·104). Classification models, that allow to identify mixtures containing TAN and BB, TAN and PB, chlorophyll and quinoline yellow with BB or PB, have been developed using methods of hierarchical cluster analysis, factor analysis (FA), partial least squares (PLS) and principal component analysis (PCA). Model solutions of dyes and 12 real objects (tarkhun, low-alcohol drinks, tonics and absinthe of various brands) were used for the classification. The best classification results were achieved at pH 1.5 using PLS and PCA. Quantitative models, based on the additivity of spectral signals and PLS, have been developed for determining the permittivity of these dyes in the simultaneous presence. In order to make it possible to analyse alcoholic drinks, the dependence of the molar attenuation coefficient on the dielectric conductivity of solvents was studied. The obtained regression equations were taken into account in the calibration for absorbance additivity. Methods for the quantitative determination of the investigated dyes were developed for the concentration range 0.2-2.0∙10-5 М.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67434434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.17721/moca.2019.200-207
I. G. Коtsiuba, G. Skyba, I. A. Skuratovskaya, S. M. Lyko
A systematic approach to environmental monitoring of small water systems and its optimization is proposed. For simplify the storage of large amounts of information, accelerate the obtaining of preliminary conclusions of water resources condition, predict the dynamics of both individual indicators and their system attributes, and develop a user-friendly interface, which is tied to the area. To carry out the research, samples of water were taken near the corresponding sections of industrial enterprises of Korosten region, as well as discharges of a storm water system. Based on the standard approach, with the help of physicochemical methods of analysis practically all the hydrochemical parameters in the studied water body were determined. The obtained results were compared with the regulatory guidelines. For systematization and maintenance of environmental monitoring, a software package has been developed, which has been tested on the results of the instrumental laboratory analysis of surface water quality of the river Uzh. The software package is developed to establish local sources of pollution, monitor potentially dangerous man-made objects, and better manage of water resources. A user-friendly interface has been developed, which is tied to the area and is easily adapted to other monitoring objects. Thanks to the developed software package, the implementation of an integrated approach to the collection and analysis of monitoring data is carried out quickly, efficiently and conveniently. The developed approach allows easy adaptation to the objects of the research and does not require significant capital investment.
{"title":"Ecological Monitoring Of Small Water Systems: Algorithm, Software Package, The Results Of Application To The Uzh River Basin (Ukraine)","authors":"I. G. Коtsiuba, G. Skyba, I. A. Skuratovskaya, S. M. Lyko","doi":"10.17721/moca.2019.200-207","DOIUrl":"https://doi.org/10.17721/moca.2019.200-207","url":null,"abstract":"A systematic approach to environmental monitoring of small water systems and its optimization is proposed. For simplify the storage of large amounts of information, accelerate the obtaining of preliminary conclusions of water resources condition, predict the dynamics of both individual indicators and their system attributes, and develop a user-friendly interface, which is tied to the area. To carry out the research, samples of water were taken near the corresponding sections of industrial enterprises of Korosten region, as well as discharges of a storm water system. Based on the standard approach, with the help of physicochemical methods of analysis practically all the hydrochemical parameters in the studied water body were determined. The obtained results were compared with the regulatory guidelines. For systematization and maintenance of environmental monitoring, a software package has been developed, which has been tested on the results of the instrumental laboratory analysis of surface water quality of the river Uzh. The software package is developed to establish local sources of pollution, monitor potentially dangerous man-made objects, and better manage of water resources. A user-friendly interface has been developed, which is tied to the area and is easily adapted to other monitoring objects. Thanks to the developed software package, the implementation of an integrated approach to the collection and analysis of monitoring data is carried out quickly, efficiently and conveniently. The developed approach allows easy adaptation to the objects of the research and does not require significant capital investment.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67434918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Tkachenko, M. Onizhuk, O. Tkachenko, L. Arenas, E. Benvenutti, Y. Gushikem, A. V. Panteleimonov
In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.
{"title":"An Electrochemical Sensor Based On Graphite Electrode Modified With Silica Containing 1-N-Propyl-3-Methylimidazolium Species For Determination Of Ascorbic Acid","authors":"A. Tkachenko, M. Onizhuk, O. Tkachenko, L. Arenas, E. Benvenutti, Y. Gushikem, A. V. Panteleimonov","doi":"10.17721/MOCA.2019.5-14","DOIUrl":"https://doi.org/10.17721/MOCA.2019.5-14","url":null,"abstract":"In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67435134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.17721/moca.2019.91-101
V. D. Kurochkin, O. Romanenko
A mathematical model was developed for calculation of types and intensities of molecular interferences and simulation of mass-spectra at GDMS analysis of non-conducting samples with the use of a secondary cathode. An improved design of the cell with Ta-secondary cathode were suggested enhancing the matrix to tantalum ion current ratio and sensitivity of the analysis in ca. 1.5 orders of magnitude. The model have been used for interpretation of complicate mass-spectra of calcium carbonate naturally doped with REE, phosphates and other impurities. Comparison calculated and experimental mass-spectra of VG9000 instrument demonstrates good agreement and allows select the most suitable isotopes and rejecting wrong molecular peaks. It have been shown that electrons in glow discharge plasma have different temperatures in different zones that reveals itself as separate Boltzmann populations of ionization levels for molecules, metal atoms and argon atoms/ions. Calcium carbonate is widely used for many application including as precursor for nano-hydroxyapatite synthesis. Calcium carbonate was precipitated from natural mine waters and was used as model object having high number of various impurities allowing to investigate the impact of complicate molecular ions, determine necessary resolving power of the GD-instruments to meet required detection limit.
{"title":"GDMS Analysis Of Calcium Carbonate Naturaly Doped By REE,\u0000Phospates And Other Impurities","authors":"V. D. Kurochkin, O. Romanenko","doi":"10.17721/moca.2019.91-101","DOIUrl":"https://doi.org/10.17721/moca.2019.91-101","url":null,"abstract":"A mathematical model was developed for calculation of types and intensities of molecular interferences and simulation of mass-spectra at GDMS analysis of non-conducting samples with the use of a secondary cathode. An improved design of the cell with Ta-secondary cathode were suggested enhancing the matrix to tantalum ion current ratio and sensitivity of the analysis in ca. 1.5 orders of magnitude. The model have been used for interpretation of complicate mass-spectra of calcium carbonate naturally doped with REE, phosphates and other impurities. Comparison calculated and experimental mass-spectra of VG9000 instrument demonstrates good agreement and allows select the most suitable isotopes and rejecting wrong molecular peaks. It have been shown that electrons in glow discharge plasma have different temperatures in different zones that reveals itself as separate Boltzmann populations of ionization levels for molecules, metal atoms and argon atoms/ions. Calcium carbonate is widely used for many application including as precursor for nano-hydroxyapatite synthesis. Calcium carbonate was precipitated from natural mine waters and was used as model object having high number of various impurities allowing to investigate the impact of complicate molecular ions, determine necessary resolving power of the GD-instruments to meet required detection limit.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67435362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.17721/moca.2019.79-90
M. I. Berdnyk, A. B. Zakharov, V. Ivanov
One of the primary tasks of analytical chemistry and QSAR/QSPR researches is building of prognostic regression equations based on descriptors sets. The one of the most important problems here is to decrease the number of descriptors in the initial descriptor set which is usually way too big. In current investigation the descriptor set is proposed to be reduced employing the least absolute shrinkage and selection operator (LASSO) approach. Decreased descriptor sets were used for calculations with application of the following QSAR/QSPR methods: ordinary least squares (OLS), the least absolute deviation (LAD) regressions and artificial neural networks (ANN). Contrary to aforementioned methods principal component regression (PCR) and partial least squares (PLS) approaches can produce solutions containing numerous descriptors. In this article we compared the viability of these two different descriptor handling ideologies in application to molecular chemical and physical properties prediction. From the obtained results it is possible to see that there are tasks for which PCR and PLS approaches can fail to produce accurate regression equations. At the same time, methods OLS and LAD that use small amount of descriptors can provide viable solutions for the same cases. It was shown that these small sets of descriptors selected with LASSO approach can be used in ANN to obtain models with even better internal validation characteristics.
{"title":"Application Of L1- Regularization Approach In QSAR Problem. Linear Regression And Artificial Neural Networks","authors":"M. I. Berdnyk, A. B. Zakharov, V. Ivanov","doi":"10.17721/moca.2019.79-90","DOIUrl":"https://doi.org/10.17721/moca.2019.79-90","url":null,"abstract":"One of the primary tasks of analytical chemistry and QSAR/QSPR researches is building of prognostic regression equations based on descriptors sets. The one of the most important problems here is to decrease the number of descriptors in the initial descriptor set which is usually way too big. In current investigation the descriptor set is proposed to be reduced employing the least absolute shrinkage and selection operator (LASSO) approach. Decreased descriptor sets were used for calculations with application of the following QSAR/QSPR methods: ordinary least squares (OLS), the least absolute deviation (LAD) regressions and artificial neural networks (ANN). Contrary to aforementioned methods principal component regression (PCR) and partial least squares (PLS) approaches can produce solutions containing numerous descriptors. In this article we compared the viability of these two different descriptor handling ideologies in application to molecular chemical and physical properties prediction. From the obtained results it is possible to see that there are tasks for which PCR and PLS approaches can fail to produce accurate regression equations. At the same time, methods OLS and LAD that use small amount of descriptors can provide viable solutions for the same cases. It was shown that these small sets of descriptors selected with LASSO approach can be used in ANN to obtain models with even better internal validation characteristics.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67435806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.17721/MOCA.2019.30-36
A. K. Trofimchuk, S. Didukh, A. Mukhina, V. Losev
Silica based adsorbents modified with polyhexamethylene guanidine and sulfonic derivatives of nitroso naphthols - nitroso-N salt (NNS) and nitroso-R salt (NRS), have been proposed for preconcentration and solid-phase photometric determination of Ni(II) in industrial solutions. Adsorbents with the surface concentration of the reagents of 1.5 and 3 μmol/g have been studied. Adsorbents with NNS functional groups quantitatively extract Ni(II) at pH 5.5-7.5, while with NRS functional groups – at pH 5.5-7.0, giving complex compounds with the composition Ni(II) : Reagent = 1 : 3. After Ni(II) adsorption the adsorbents became orange (λ = 510 нм) or brown (λ = 490 нм) for NNS and NRS respectively. The pH range of maximum color intensity coincides with the pH range of the quantitative extraction of Ni(II). The procedure of solid-phase photometric determination of Ni(II) in form of diffuse reflectance spectroscopy has been developed. The analytical range of the procedure is 0.1 – 3.0 μg of Ni(II) per 0.1 g of the adsorbent with the surface concentration of the reagent of 1.5 μmol/g and 0.15 – 6 μg of Ni(II) per 0.1g of the adsorbent with the surface concentration of the reagent of 3 μmol/g. The procedure was used for determination of Ni(II) in the rinsing and waste waters of galvanic manufactory. The results accuracy was confirmed by ICP-OES analysis.
{"title":"Preconcentration And Determination Of Nickel Ions Using Silica With Functional Groups Of Sulfonic Derivatives Of Nitroso Naphthols","authors":"A. K. Trofimchuk, S. Didukh, A. Mukhina, V. Losev","doi":"10.17721/MOCA.2019.30-36","DOIUrl":"https://doi.org/10.17721/MOCA.2019.30-36","url":null,"abstract":"Silica based adsorbents modified with polyhexamethylene guanidine and sulfonic derivatives of nitroso naphthols - nitroso-N salt (NNS) and nitroso-R salt (NRS), have been proposed for preconcentration and solid-phase photometric determination of Ni(II) in industrial solutions. Adsorbents with the surface concentration of the reagents of 1.5 and 3 μmol/g have been studied. Adsorbents with NNS functional groups quantitatively extract Ni(II) at pH 5.5-7.5, while with NRS functional groups – at pH 5.5-7.0, giving complex compounds with the composition Ni(II) : Reagent = 1 : 3. After Ni(II) adsorption the adsorbents became orange (λ = 510 нм) or brown (λ = 490 нм) for NNS and NRS respectively. The pH range of maximum color intensity coincides with the pH range of the quantitative extraction of Ni(II). The procedure of solid-phase photometric determination of Ni(II) in form of diffuse reflectance spectroscopy has been developed. The analytical range of the procedure is 0.1 – 3.0 μg of Ni(II) per 0.1 g of the adsorbent with the surface concentration of the reagent of 1.5 μmol/g and 0.15 – 6 μg of Ni(II) per 0.1g of the adsorbent with the surface concentration of the reagent of 3 μmol/g. The procedure was used for determination of Ni(II) in the rinsing and waste waters of galvanic manufactory. The results accuracy was confirmed by ICP-OES analysis.","PeriodicalId":18626,"journal":{"name":"Methods and Objects of Chemical Analysis","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67434868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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