TY  - JOUR
AU  - Relić, Dubravka
AU  - Heberger, Karoly
AU  - Sakan, Sanja
AU  - Skrbic, Biljana
AU  - Popović, Aleksandar R.
AU  - Đorđević, Dragana
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2324
AB  - This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pancevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Chemosphere
T1  - Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods
VL  - 198
SP  - 103
EP  - 110
DO  - 10.1016/j.chemosphere.2017.12.200
ER  - 

@article{
author = "Relić, Dubravka and Heberger, Karoly and Sakan, Sanja and Skrbic, Biljana and Popović, Aleksandar R. and Đorđević, Dragana",
year = "2018",
abstract = "This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pancevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Chemosphere",
title = "Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods",
volume = "198",
pages = "103-110",
doi = "10.1016/j.chemosphere.2017.12.200"
}

Relić, D., Heberger, K., Sakan, S., Skrbic, B., Popović, A. R.,& Đorđević, D.. (2018). Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods. in Chemosphere
Oxford : Pergamon-Elsevier Science Ltd., 198, 103-110.
https://doi.org/10.1016/j.chemosphere.2017.12.200

Relić D, Heberger K, Sakan S, Skrbic B, Popović AR, Đorđević D. Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods. in Chemosphere. 2018;198:103-110.
doi:10.1016/j.chemosphere.2017.12.200 .

Relić, Dubravka, Heberger, Karoly, Sakan, Sanja, Skrbic, Biljana, Popović, Aleksandar R., Đorđević, Dragana, "Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods" in Chemosphere, 198 (2018):103-110,
https://doi.org/10.1016/j.chemosphere.2017.12.200 . .

TY  - JOUR
AU  - Relić, Dubravka
AU  - Heberger, Karoly
AU  - Sakan, Sanja
AU  - Skrbic, Biljana
AU  - Popović, Aleksandar R.
AU  - Đorđević, Dragana
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2934
AB  - This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pancevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Chemosphere
T1  - Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods
VL  - 198
SP  - 103
EP  - 110
DO  - 10.1016/j.chemosphere.2017.12.200
ER  - 

@article{
author = "Relić, Dubravka and Heberger, Karoly and Sakan, Sanja and Skrbic, Biljana and Popović, Aleksandar R. and Đorđević, Dragana",
year = "2018",
abstract = "This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pancevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Chemosphere",
title = "Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods",
volume = "198",
pages = "103-110",
doi = "10.1016/j.chemosphere.2017.12.200"
}

Relić, D., Heberger, K., Sakan, S., Skrbic, B., Popović, A. R.,& Đorđević, D.. (2018). Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods. in Chemosphere
Oxford : Pergamon-Elsevier Science Ltd., 198, 103-110.
https://doi.org/10.1016/j.chemosphere.2017.12.200

Relić D, Heberger K, Sakan S, Skrbic B, Popović AR, Đorđević D. Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods. in Chemosphere. 2018;198:103-110.
doi:10.1016/j.chemosphere.2017.12.200 .

Relić, Dubravka, Heberger, Karoly, Sakan, Sanja, Skrbic, Biljana, Popović, Aleksandar R., Đorđević, Dragana, "Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods" in Chemosphere, 198 (2018):103-110,
https://doi.org/10.1016/j.chemosphere.2017.12.200 . .

TY  - JOUR
AU  - Andrić, Filip
AU  - Bajusz, David
AU  - Racz, Anita
AU  - Šegan, Sandra
AU  - Heberger, Karoly
PY  - 2016
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1848
AB  - Needs for fast, yet reliable means of assessing the lipophilicities of diverse compounds resulted in the development of various in silico and chromatographic approaches that are faster, cheaper, and greener compared to the traditional shake-flask method. However, at present no accepted "standard" approach exists for their comparison and selection of the most appropriate one(s). This is of utmost importance when it comes to the development of new lipophilicity indices, or the assessment of the lipophilicity of newly synthesized compounds. In this study, 50 well-known, diverse compounds of significant pharmaceutical and environmental importance have been selected and examined. Octanol-water partition coefficients have been measured with the shake-flask method for most of them. Their retentions have been studied in typical reversed thin-layer chromatographic systems, involving the most frequently employed stationary phases (octadecyl- and cyano-modified silica), and acetonitrile and methanol as mobile phase constituents. Twelve computationally estimated logP-s and twenty chromatographic indices together with the shake-flask octanol-water partition coefficient have been investigated with classical chemometric approaches such as principal component analysis (PCA), hierarchical cluster analysis (HCA), Pearson's and Spearman's correlation matrices, as well as novel non-parametric methods: sum of ranking differences (SRD) and generalized pairwise correlation method (GPCM). Novel SRD and GPCM methods have been introduced based on the Comparisons with One VAriable (lipophilicity metric) at a Time (COVAT). For the visualization of COVAT results, a heatmap format was introduced. Analysis of variance (ANOVA) was applied to reveal the dominant factors between computational logPs and various chromatographic measures. In consensus-based comparisons, the shake-flask method performed the best, closely followed by computational estimates, while the chromatographic estimates often overlap with in silico assessments, mostly with methods involving octadecyl-modified silica stationary phases. The ones that employ cyano-modified silica perform generally worse. The introduction of alternative coloring schemes for the covariance matrices and SRD/GPCM heatmaps enables the discovery of intrinsic relationships among lipophilicity scales and the selection of best/worst measures. Closest to the recommended logK(ow) values are ClogP and the first principal component scores obtained on octadecyl-silica stationary phase in combination with methanol-water mobile phase, while the usage of slopes derived from Soczewinski-Matyisik equation should be avoided.
PB  - Elsevier
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Multivariate assessment of lipophilicity scales-computational and reversed phase thin-layer chromatographic indices
VL  - 127
SP  - 81
EP  - 93
DO  - 10.1016/j.jpba.2016.04.001
ER  - 

@article{
author = "Andrić, Filip and Bajusz, David and Racz, Anita and Šegan, Sandra and Heberger, Karoly",
year = "2016",
abstract = "Needs for fast, yet reliable means of assessing the lipophilicities of diverse compounds resulted in the development of various in silico and chromatographic approaches that are faster, cheaper, and greener compared to the traditional shake-flask method. However, at present no accepted "standard" approach exists for their comparison and selection of the most appropriate one(s). This is of utmost importance when it comes to the development of new lipophilicity indices, or the assessment of the lipophilicity of newly synthesized compounds. In this study, 50 well-known, diverse compounds of significant pharmaceutical and environmental importance have been selected and examined. Octanol-water partition coefficients have been measured with the shake-flask method for most of them. Their retentions have been studied in typical reversed thin-layer chromatographic systems, involving the most frequently employed stationary phases (octadecyl- and cyano-modified silica), and acetonitrile and methanol as mobile phase constituents. Twelve computationally estimated logP-s and twenty chromatographic indices together with the shake-flask octanol-water partition coefficient have been investigated with classical chemometric approaches such as principal component analysis (PCA), hierarchical cluster analysis (HCA), Pearson's and Spearman's correlation matrices, as well as novel non-parametric methods: sum of ranking differences (SRD) and generalized pairwise correlation method (GPCM). Novel SRD and GPCM methods have been introduced based on the Comparisons with One VAriable (lipophilicity metric) at a Time (COVAT). For the visualization of COVAT results, a heatmap format was introduced. Analysis of variance (ANOVA) was applied to reveal the dominant factors between computational logPs and various chromatographic measures. In consensus-based comparisons, the shake-flask method performed the best, closely followed by computational estimates, while the chromatographic estimates often overlap with in silico assessments, mostly with methods involving octadecyl-modified silica stationary phases. The ones that employ cyano-modified silica perform generally worse. The introduction of alternative coloring schemes for the covariance matrices and SRD/GPCM heatmaps enables the discovery of intrinsic relationships among lipophilicity scales and the selection of best/worst measures. Closest to the recommended logK(ow) values are ClogP and the first principal component scores obtained on octadecyl-silica stationary phase in combination with methanol-water mobile phase, while the usage of slopes derived from Soczewinski-Matyisik equation should be avoided.",
publisher = "Elsevier",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Multivariate assessment of lipophilicity scales-computational and reversed phase thin-layer chromatographic indices",
volume = "127",
pages = "81-93",
doi = "10.1016/j.jpba.2016.04.001"
}

Andrić, F., Bajusz, D., Racz, A., Šegan, S.,& Heberger, K.. (2016). Multivariate assessment of lipophilicity scales-computational and reversed phase thin-layer chromatographic indices. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier., 127, 81-93.
https://doi.org/10.1016/j.jpba.2016.04.001

Andrić F, Bajusz D, Racz A, Šegan S, Heberger K. Multivariate assessment of lipophilicity scales-computational and reversed phase thin-layer chromatographic indices. in Journal of Pharmaceutical and Biomedical Analysis. 2016;127:81-93.
doi:10.1016/j.jpba.2016.04.001 .

Andrić, Filip, Bajusz, David, Racz, Anita, Šegan, Sandra, Heberger, Karoly, "Multivariate assessment of lipophilicity scales-computational and reversed phase thin-layer chromatographic indices" in Journal of Pharmaceutical and Biomedical Analysis, 127 (2016):81-93,
https://doi.org/10.1016/j.jpba.2016.04.001 . .