TY  - JOUR
AU  - Savić, Andrija B.
AU  - Čokeša, Đuro
AU  - Savić-Biserčić, Marjetka
AU  - Janković-Častvan, Ivona
AU  - Petrović, Rada
AU  - Živković, Ljiljana
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4233
AB  - Natural filtration material tuff (T) was modified by coating with nano-sized magnetite. The grain fraction of 0.6-1.9 mm was submitted to hydrothermal synthesis of magnetite. Thus formed magnetite modified tuff (MMT) was characterized in terms of Fe-content, N2 adsorption-desorption isotherm, SEM, zeta potential-pH analyses and adsorption behavior towards phosphates/arsenates in batch and column conditions. Elemental analysis showed that 36.54 mg g(-1) of magnetite was attached to the porous tuff grains. This modification changed pore structure and specific surface area. An increase of cca 35% in Sp value was obtained. Batch experiments proved that MMT was 4-5 times more efficient in removal of phosphates/ arsenates than non-modified T. The maximum sorption capacities of phosphates calculated based on Langmuir equation were 0.45 and 1.91 mg g(-1), while those for arsenate were 0.551 m g(-1) and 2.36 mg g(-1) for T and MMT, respectively. The intra-particle diffusion model was the most suited for describing the adsorption process of phosphate and arsenate onto MMT. Fixed-bed column data corroborated batch results, i.e. MMT was 6 times superior in contaminant adsorption than T. Modification with magnetite improved T potential for usage in water treatment applications: its filtration ability remained unchanged, while adsorption capacity for phosphates/arsenates removal was improved.
PB  - Elsevier Science Bv, Amsterdam
T2  - Advanced Powder Technology
T1  - Multifunctional use of magnetite-coated tuff grains in water treatment: Removal of arsenates and phosphates
EP  - 1695
IS  - 8
SP  - 1687
VL  - 30
DO  - 10.1016/j.apt.2019.05.020
ER  - 

@article{
author = "Savić, Andrija B. and Čokeša, Đuro and Savić-Biserčić, Marjetka and Janković-Častvan, Ivona and Petrović, Rada and Živković, Ljiljana",
year = "2019",
abstract = "Natural filtration material tuff (T) was modified by coating with nano-sized magnetite. The grain fraction of 0.6-1.9 mm was submitted to hydrothermal synthesis of magnetite. Thus formed magnetite modified tuff (MMT) was characterized in terms of Fe-content, N2 adsorption-desorption isotherm, SEM, zeta potential-pH analyses and adsorption behavior towards phosphates/arsenates in batch and column conditions. Elemental analysis showed that 36.54 mg g(-1) of magnetite was attached to the porous tuff grains. This modification changed pore structure and specific surface area. An increase of cca 35% in Sp value was obtained. Batch experiments proved that MMT was 4-5 times more efficient in removal of phosphates/ arsenates than non-modified T. The maximum sorption capacities of phosphates calculated based on Langmuir equation were 0.45 and 1.91 mg g(-1), while those for arsenate were 0.551 m g(-1) and 2.36 mg g(-1) for T and MMT, respectively. The intra-particle diffusion model was the most suited for describing the adsorption process of phosphate and arsenate onto MMT. Fixed-bed column data corroborated batch results, i.e. MMT was 6 times superior in contaminant adsorption than T. Modification with magnetite improved T potential for usage in water treatment applications: its filtration ability remained unchanged, while adsorption capacity for phosphates/arsenates removal was improved.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Advanced Powder Technology",
title = "Multifunctional use of magnetite-coated tuff grains in water treatment: Removal of arsenates and phosphates",
pages = "1695-1687",
number = "8",
volume = "30",
doi = "10.1016/j.apt.2019.05.020"
}

Savić, A. B., Čokeša, Đ., Savić-Biserčić, M., Janković-Častvan, I., Petrović, R.,& Živković, L.. (2019). Multifunctional use of magnetite-coated tuff grains in water treatment: Removal of arsenates and phosphates. in Advanced Powder Technology
Elsevier Science Bv, Amsterdam., 30(8), 1687-1695.
https://doi.org/10.1016/j.apt.2019.05.020

Savić AB, Čokeša Đ, Savić-Biserčić M, Janković-Častvan I, Petrović R, Živković L. Multifunctional use of magnetite-coated tuff grains in water treatment: Removal of arsenates and phosphates. in Advanced Powder Technology. 2019;30(8):1687-1695.
doi:10.1016/j.apt.2019.05.020 .

Savić, Andrija B., Čokeša, Đuro, Savić-Biserčić, Marjetka, Janković-Častvan, Ivona, Petrović, Rada, Živković, Ljiljana, "Multifunctional use of magnetite-coated tuff grains in water treatment: Removal of arsenates and phosphates" in Advanced Powder Technology, 30, no. 8 (2019):1687-1695,
https://doi.org/10.1016/j.apt.2019.05.020 . .

TY  - JOUR
AU  - Savić, Andrija B.
AU  - Čokeša, Đuro
AU  - Lazarević, Slavica
AU  - Jokić, Bojan
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
AU  - Živković, Ljiljana
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3356
AB  - This study demonstrates that PEG-assisted hydrothermal synthesis provides a convenient and eco-friendly route to fabrication of mesoporous magnetite with enhanced capacity for phosphate removal, excellent potential for magnetic separation and good reusability. Adsorption of phosphate onto 4 laboratory prepared magnetite powders was investigated in a systematic manner. Powders were synthesized in poly(ethylene) glycol-free or assisted conditions (PEGs 400 and 20,000 at varied PEG/water ratio), and characterized in terms of crystalline structure, and magnetic, morphological, textural, and acid-base properties. PEG acted as a powerful pore forming agent, the PEG/water ratio being the key factor in developing the surface area and mesoporosity of magnetite. Uptake capacity for phosphates increased with an increase in surface area and pore volume. PEG 20,000 at a ratio of 3:1 gave the best result. This mesoporous (D-max = 11 nm), nano-scale ( lt 10 nm) magnetite was ca. 9 times more efficient than nonporous micrometric powder derived from PEG-free synthesis (Langmuir maximum capacity, q(m) = 26.2 vs. 3.0 mg g(-1)). The adsorption was pH-dependent, in accord with variations in zeta potential of magnetite. Opposite shifts of isoelectric point and point of zero charge confirmed specific adsorption of phosphates at water/magnetite interface which proceeded via replacement of surface hydroxyls and sulfates.
PB  - Elsevier Science Bv, Amsterdam
T2  - Powder Technology
T1  - Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process
EP  - 519
SP  - 511
VL  - 301
DO  - 10.1016/j.powtec.2016.06.028
ER  - 

@article{
author = "Savić, Andrija B. and Čokeša, Đuro and Lazarević, Slavica and Jokić, Bojan and Janaćković, Đorđe and Petrović, Rada and Živković, Ljiljana",
year = "2016",
abstract = "This study demonstrates that PEG-assisted hydrothermal synthesis provides a convenient and eco-friendly route to fabrication of mesoporous magnetite with enhanced capacity for phosphate removal, excellent potential for magnetic separation and good reusability. Adsorption of phosphate onto 4 laboratory prepared magnetite powders was investigated in a systematic manner. Powders were synthesized in poly(ethylene) glycol-free or assisted conditions (PEGs 400 and 20,000 at varied PEG/water ratio), and characterized in terms of crystalline structure, and magnetic, morphological, textural, and acid-base properties. PEG acted as a powerful pore forming agent, the PEG/water ratio being the key factor in developing the surface area and mesoporosity of magnetite. Uptake capacity for phosphates increased with an increase in surface area and pore volume. PEG 20,000 at a ratio of 3:1 gave the best result. This mesoporous (D-max = 11 nm), nano-scale ( lt 10 nm) magnetite was ca. 9 times more efficient than nonporous micrometric powder derived from PEG-free synthesis (Langmuir maximum capacity, q(m) = 26.2 vs. 3.0 mg g(-1)). The adsorption was pH-dependent, in accord with variations in zeta potential of magnetite. Opposite shifts of isoelectric point and point of zero charge confirmed specific adsorption of phosphates at water/magnetite interface which proceeded via replacement of surface hydroxyls and sulfates.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Powder Technology",
title = "Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process",
pages = "519-511",
volume = "301",
doi = "10.1016/j.powtec.2016.06.028"
}

Savić, A. B., Čokeša, Đ., Lazarević, S., Jokić, B., Janaćković, Đ., Petrović, R.,& Živković, L.. (2016). Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process. in Powder Technology
Elsevier Science Bv, Amsterdam., 301, 511-519.
https://doi.org/10.1016/j.powtec.2016.06.028

Savić AB, Čokeša Đ, Lazarević S, Jokić B, Janaćković Đ, Petrović R, Živković L. Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process. in Powder Technology. 2016;301:511-519.
doi:10.1016/j.powtec.2016.06.028 .

Savić, Andrija B., Čokeša, Đuro, Lazarević, Slavica, Jokić, Bojan, Janaćković, Đorđe, Petrović, Rada, Živković, Ljiljana, "Tailoring of magnetite powder properties for enhanced phosphate removal: Effect of PEG addition in the synthesis process" in Powder Technology, 301 (2016):511-519,
https://doi.org/10.1016/j.powtec.2016.06.028 . .

TY  - JOUR
AU  - Sremac, Snežana
AU  - Popović, Aleksandar R.
AU  - Todorović, Žaklina
AU  - Čokeša, Đuro
AU  - Onjia, Antonije
PY  - 2008
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1347
AB  - An interpretative strategy (factorial design experimentation + total resolution analysis + chromatogram simulation) was employed to optimize the separation of 16 polycyclic aromatic hydrocarbons (PAHs) (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(k)fluoranthene, benzo(b)fluoranthene, benzo(a)pyrene, indeno(1,2,3-c,d)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene) in temperature-programmed gas chromatography (GC). Also, the retention behavior of PAHs in the same GC system was studied by a feed-forward artificial neural network (ANN). GC separation was investigated as a function of one (linear temperature ramp) or two (linear temperature ramp+the final hold temperature) variables. The applied interpretative approach resulted in rather good agreement between the measured and the predicted retention times for PAHs in both one and two variable modeling. The ANN model, strongly affected by the number of input experiments, was shown to be less effective for one variable used, but quite successful when two input variables were used. All PAHs, including difficult to separate peak pairs (benzo(k)fluoranthene/benzo(b)fluoranthene and indeno(1,2,3-c,d)pyrene/dibenzo(a,h)anthracene), were separated in a standard (5% phenyl-95% climethylpolysiloxane) capillary column at an optimum temperature ramp of 8.0 degrees C/min and final hold temperature in the range of 260-320 degrees C.
PB  - Elsevier, Amsterdam
T2  - Talanta
T1  - Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons
EP  - 71
IS  - 1
SP  - 66
VL  - 76
DO  - 10.1016/j.talanta.2008.02.004
ER  - 

@article{
author = "Sremac, Snežana and Popović, Aleksandar R. and Todorović, Žaklina and Čokeša, Đuro and Onjia, Antonije",
year = "2008",
abstract = "An interpretative strategy (factorial design experimentation + total resolution analysis + chromatogram simulation) was employed to optimize the separation of 16 polycyclic aromatic hydrocarbons (PAHs) (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(k)fluoranthene, benzo(b)fluoranthene, benzo(a)pyrene, indeno(1,2,3-c,d)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene) in temperature-programmed gas chromatography (GC). Also, the retention behavior of PAHs in the same GC system was studied by a feed-forward artificial neural network (ANN). GC separation was investigated as a function of one (linear temperature ramp) or two (linear temperature ramp+the final hold temperature) variables. The applied interpretative approach resulted in rather good agreement between the measured and the predicted retention times for PAHs in both one and two variable modeling. The ANN model, strongly affected by the number of input experiments, was shown to be less effective for one variable used, but quite successful when two input variables were used. All PAHs, including difficult to separate peak pairs (benzo(k)fluoranthene/benzo(b)fluoranthene and indeno(1,2,3-c,d)pyrene/dibenzo(a,h)anthracene), were separated in a standard (5% phenyl-95% climethylpolysiloxane) capillary column at an optimum temperature ramp of 8.0 degrees C/min and final hold temperature in the range of 260-320 degrees C.",
publisher = "Elsevier, Amsterdam",
journal = "Talanta",
title = "Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons",
pages = "71-66",
number = "1",
volume = "76",
doi = "10.1016/j.talanta.2008.02.004"
}

Sremac, S., Popović, A. R., Todorović, Ž., Čokeša, Đ.,& Onjia, A.. (2008). Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons. in Talanta
Elsevier, Amsterdam., 76(1), 66-71.
https://doi.org/10.1016/j.talanta.2008.02.004

Sremac S, Popović AR, Todorović Ž, Čokeša Đ, Onjia A. Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons. in Talanta. 2008;76(1):66-71.
doi:10.1016/j.talanta.2008.02.004 .

Sremac, Snežana, Popović, Aleksandar R., Todorović, Žaklina, Čokeša, Đuro, Onjia, Antonije, "Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons" in Talanta, 76, no. 1 (2008):66-71,
https://doi.org/10.1016/j.talanta.2008.02.004 . .

TY  - JOUR
AU  - Vasiljević, Tatjana
AU  - Onjia, Antonije
AU  - Čokeša, Đuro
AU  - Laušević, Mila
PY  - 2004
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/702
AB  - An artificial neural network (ANN) model for the prediction of retention times in high-performance liquid chromatography (HPLC) was developed and optimized. A three-layer feed-forward ANN has been used to model retention behavior of nine phenols as a function of mobile phase composition (methanol-acetic acid mobile phase). The number of hidden layer nodes, number of iteration steps and the number of experimental data points used for training set were optimized. By using a relatively small amount of experimental data (25 experimental data points in the training set), a very accurate prediction of the retention (percentage normalized differences between the predicted and the experimental data less than 0.6%) was obtained. It was shown that the prediction ability of ANN model linearly decreased with the reduction of number of experiments for the training data set. The results obtained demonstrate that ANN offers a straightforward way for retention modeling in isocratic HPLC separation of a complex mixture of compounds widely different in pK(a) and log K-ow values.
PB  - Elsevier, Amsterdam
T2  - Talanta
T1  - Optimization of artificial neural network for retention modeling in high-performance liquid chromatography
EP  - 790
IS  - 3
SP  - 785
VL  - 64
DO  - 10.1016/j.talanta.2004.03.032
ER  - 

@article{
author = "Vasiljević, Tatjana and Onjia, Antonije and Čokeša, Đuro and Laušević, Mila",
year = "2004",
abstract = "An artificial neural network (ANN) model for the prediction of retention times in high-performance liquid chromatography (HPLC) was developed and optimized. A three-layer feed-forward ANN has been used to model retention behavior of nine phenols as a function of mobile phase composition (methanol-acetic acid mobile phase). The number of hidden layer nodes, number of iteration steps and the number of experimental data points used for training set were optimized. By using a relatively small amount of experimental data (25 experimental data points in the training set), a very accurate prediction of the retention (percentage normalized differences between the predicted and the experimental data less than 0.6%) was obtained. It was shown that the prediction ability of ANN model linearly decreased with the reduction of number of experiments for the training data set. The results obtained demonstrate that ANN offers a straightforward way for retention modeling in isocratic HPLC separation of a complex mixture of compounds widely different in pK(a) and log K-ow values.",
publisher = "Elsevier, Amsterdam",
journal = "Talanta",
title = "Optimization of artificial neural network for retention modeling in high-performance liquid chromatography",
pages = "790-785",
number = "3",
volume = "64",
doi = "10.1016/j.talanta.2004.03.032"
}

Vasiljević, T., Onjia, A., Čokeša, Đ.,& Laušević, M.. (2004). Optimization of artificial neural network for retention modeling in high-performance liquid chromatography. in Talanta
Elsevier, Amsterdam., 64(3), 785-790.
https://doi.org/10.1016/j.talanta.2004.03.032

Vasiljević T, Onjia A, Čokeša Đ, Laušević M. Optimization of artificial neural network for retention modeling in high-performance liquid chromatography. in Talanta. 2004;64(3):785-790.
doi:10.1016/j.talanta.2004.03.032 .

Vasiljević, Tatjana, Onjia, Antonije, Čokeša, Đuro, Laušević, Mila, "Optimization of artificial neural network for retention modeling in high-performance liquid chromatography" in Talanta, 64, no. 3 (2004):785-790,
https://doi.org/10.1016/j.talanta.2004.03.032 . .

TY  - JOUR
AU  - Onjia, Antonije
AU  - Milonjić, Slobodan K.
AU  - Čokeša, Đuro
AU  - Čomor, Mirjana
AU  - Miljević, Nada R.
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/534
AB  - Colloidal particles of chromia have been prepared by forced hydrolysis of an aqueous solution containing chromium chloride hexahydrate. At elevated temperature, a controlled addition of potassium hydroxide yielded colloidal chromia particles. After the sol coagulation, amorphous dried residues (I) were converted to crystalline form (II) by heating at 1073 K. The thermal treatment was also accompanied by a reduction in both surface area (from 75 to 9 m(2)/g) and point of zero charge (pH(pzc); from 4.7 to 4.0). Chromia dissolution over the studied pH range (pH = 2-12) exhibits a parabolic trend, with minimum solubility at pH(pzc).
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Materials Research Bulletin
T1  - Characterization of colloidal chromia particles obtained by forced hydrolysis
EP  - 1339
IS  - 8
SP  - 1329
VL  - 38
DO  - 10.1016/S0025-5408(03)00137-5
ER  - 

@article{
author = "Onjia, Antonije and Milonjić, Slobodan K. and Čokeša, Đuro and Čomor, Mirjana and Miljević, Nada R.",
year = "2003",
abstract = "Colloidal particles of chromia have been prepared by forced hydrolysis of an aqueous solution containing chromium chloride hexahydrate. At elevated temperature, a controlled addition of potassium hydroxide yielded colloidal chromia particles. After the sol coagulation, amorphous dried residues (I) were converted to crystalline form (II) by heating at 1073 K. The thermal treatment was also accompanied by a reduction in both surface area (from 75 to 9 m(2)/g) and point of zero charge (pH(pzc); from 4.7 to 4.0). Chromia dissolution over the studied pH range (pH = 2-12) exhibits a parabolic trend, with minimum solubility at pH(pzc).",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Materials Research Bulletin",
title = "Characterization of colloidal chromia particles obtained by forced hydrolysis",
pages = "1339-1329",
number = "8",
volume = "38",
doi = "10.1016/S0025-5408(03)00137-5"
}

Onjia, A., Milonjić, S. K., Čokeša, Đ., Čomor, M.,& Miljević, N. R.. (2003). Characterization of colloidal chromia particles obtained by forced hydrolysis. in Materials Research Bulletin
Pergamon-Elsevier Science Ltd, Oxford., 38(8), 1329-1339.
https://doi.org/10.1016/S0025-5408(03)00137-5

Onjia A, Milonjić SK, Čokeša Đ, Čomor M, Miljević NR. Characterization of colloidal chromia particles obtained by forced hydrolysis. in Materials Research Bulletin. 2003;38(8):1329-1339.
doi:10.1016/S0025-5408(03)00137-5 .

Onjia, Antonije, Milonjić, Slobodan K., Čokeša, Đuro, Čomor, Mirjana, Miljević, Nada R., "Characterization of colloidal chromia particles obtained by forced hydrolysis" in Materials Research Bulletin, 38, no. 8 (2003):1329-1339,
https://doi.org/10.1016/S0025-5408(03)00137-5 . .

TY  - JOUR
AU  - Onjia, Antonije
AU  - Vasiljević, Tatjana
AU  - Čokeša, Đuro
AU  - Laušević, Mila
PY  - 2002
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/470
AB  - The parameters for the development of a chromatographic (HPLC) method and its validation are discused in the paper. Chromatographic analysis involves a multi-step procedure consisting of sample collection, pretreatment instrumental measurements and data processing. Emphasize was placed on the instrumental part of the analysis presuming that the contributions of the other variables were minor. The roles of precision, accuracy, detection limit, quantification limit, specificity, selectivity, range, linearity and robustness, as well as system suitability in the analytical application of chromatography were described. Recommendations for the validation of these parameters according to ICH and FDA guidelines are given. The criteria of validation described above can be almost completely applied to other instrumental chromatographic techniques such as GC, GC-MS, HPTLC, etc.
AB  - U radu su razmatrani parametri za razvoj i validaciju hromatografske analitičke metode. Opisana je uloga preciznosti, tačnosti, granice detekcije, granice kvantifikativnog određivanja, specifičnosti, opsega linearnosti i robustnosti, kao i pogodnosti sistema u analitičkoj primeni hromatografije. Date su preporuke za ove parametre u skladu sa ICH i FDA regulativom.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Validation of chromatographic analysis
T1  - Validacija hromatografske analize
EP  - 79
IS  - 2
SP  - 76
VL  - 56
DO  - 10.2298/HEMIND0202076O
ER  - 

@article{
author = "Onjia, Antonije and Vasiljević, Tatjana and Čokeša, Đuro and Laušević, Mila",
year = "2002",
abstract = "The parameters for the development of a chromatographic (HPLC) method and its validation are discused in the paper. Chromatographic analysis involves a multi-step procedure consisting of sample collection, pretreatment instrumental measurements and data processing. Emphasize was placed on the instrumental part of the analysis presuming that the contributions of the other variables were minor. The roles of precision, accuracy, detection limit, quantification limit, specificity, selectivity, range, linearity and robustness, as well as system suitability in the analytical application of chromatography were described. Recommendations for the validation of these parameters according to ICH and FDA guidelines are given. The criteria of validation described above can be almost completely applied to other instrumental chromatographic techniques such as GC, GC-MS, HPTLC, etc., U radu su razmatrani parametri za razvoj i validaciju hromatografske analitičke metode. Opisana je uloga preciznosti, tačnosti, granice detekcije, granice kvantifikativnog određivanja, specifičnosti, opsega linearnosti i robustnosti, kao i pogodnosti sistema u analitičkoj primeni hromatografije. Date su preporuke za ove parametre u skladu sa ICH i FDA regulativom.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Validation of chromatographic analysis, Validacija hromatografske analize",
pages = "79-76",
number = "2",
volume = "56",
doi = "10.2298/HEMIND0202076O"
}

Onjia, A., Vasiljević, T., Čokeša, Đ.,& Laušević, M.. (2002). Validation of chromatographic analysis. in Hemijska industrija
Association of Chemical Engineers of Serbia., 56(2), 76-79.
https://doi.org/10.2298/HEMIND0202076O

Onjia A, Vasiljević T, Čokeša Đ, Laušević M. Validation of chromatographic analysis. in Hemijska industrija. 2002;56(2):76-79.
doi:10.2298/HEMIND0202076O .

Onjia, Antonije, Vasiljević, Tatjana, Čokeša, Đuro, Laušević, Mila, "Validation of chromatographic analysis" in Hemijska industrija, 56, no. 2 (2002):76-79,
https://doi.org/10.2298/HEMIND0202076O . .

TY  - JOUR
AU  - Onjia, Antonije
AU  - Vasiljević, Tatjana
AU  - Čokeša, Đuro
AU  - Laušević, Mila
PY  - 2002
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/448
AB  - A multifactor optimization strategy was utilized to predict the isocratic HPLC separation of nine phenols. The retention behavior was studied as a function of changing eluent (methanol – acetic acid) composition. The predicted and measured retentions are in rather good agreement. To locate the optimum in the factor space, the normalized resolution product criterion was applied. In virtually every case, the resolution is limited by the separation of the 2-chlorophenol and 2,4-dinitrophenol pair.
AB  - U radu je korišćena metoda simultane multifaktorske optimizacije za teorijsko predviđanje separacije devet fenola metodom HPLC u izokratskim uslovima. Retencija fenola je ispitivana u funkciji sastava mobilne faze (sirćetne kiseline i metanola). Teorijski dobijena retenciona vremena ne odstupaju značajno od eksperimentalnih. Kao kriterijum za ocenu kvaliteta separacije, u cilju lociranja optimuma u faktorskom prostoru, korišćen je normalizovani rezolucioni produkt. U svim eksperimentalnim uslovima separacija 2-hlorofenola i 2,4-dinitrofenola diktira totalnu rezoluciju u sistemu.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Factorial design in isocratic high-performance liquid chromatography of phenolic compounds
T1  - Faktorski dizajn u izokratskoj tečnoj hromatografiji (HPLC) fenola
EP  - 751
IS  - 11
SP  - 745
VL  - 67
UR  - https://hdl.handle.net/21.15107/rcub_technorep_448
ER  - 

@article{
author = "Onjia, Antonije and Vasiljević, Tatjana and Čokeša, Đuro and Laušević, Mila",
year = "2002",
abstract = "A multifactor optimization strategy was utilized to predict the isocratic HPLC separation of nine phenols. The retention behavior was studied as a function of changing eluent (methanol – acetic acid) composition. The predicted and measured retentions are in rather good agreement. To locate the optimum in the factor space, the normalized resolution product criterion was applied. In virtually every case, the resolution is limited by the separation of the 2-chlorophenol and 2,4-dinitrophenol pair., U radu je korišćena metoda simultane multifaktorske optimizacije za teorijsko predviđanje separacije devet fenola metodom HPLC u izokratskim uslovima. Retencija fenola je ispitivana u funkciji sastava mobilne faze (sirćetne kiseline i metanola). Teorijski dobijena retenciona vremena ne odstupaju značajno od eksperimentalnih. Kao kriterijum za ocenu kvaliteta separacije, u cilju lociranja optimuma u faktorskom prostoru, korišćen je normalizovani rezolucioni produkt. U svim eksperimentalnim uslovima separacija 2-hlorofenola i 2,4-dinitrofenola diktira totalnu rezoluciju u sistemu.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Factorial design in isocratic high-performance liquid chromatography of phenolic compounds, Faktorski dizajn u izokratskoj tečnoj hromatografiji (HPLC) fenola",
pages = "751-745",
number = "11",
volume = "67",
url = "https://hdl.handle.net/21.15107/rcub_technorep_448"
}

Onjia, A., Vasiljević, T., Čokeša, Đ.,& Laušević, M.. (2002). Factorial design in isocratic high-performance liquid chromatography of phenolic compounds. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 67(11), 745-751.
https://hdl.handle.net/21.15107/rcub_technorep_448

Onjia A, Vasiljević T, Čokeša Đ, Laušević M. Factorial design in isocratic high-performance liquid chromatography of phenolic compounds. in Journal of the Serbian Chemical Society. 2002;67(11):745-751.
https://hdl.handle.net/21.15107/rcub_technorep_448 .

Onjia, Antonije, Vasiljević, Tatjana, Čokeša, Đuro, Laušević, Mila, "Factorial design in isocratic high-performance liquid chromatography of phenolic compounds" in Journal of the Serbian Chemical Society, 67, no. 11 (2002):745-751,
https://hdl.handle.net/21.15107/rcub_technorep_448 .

TY  - CONF
AU  - Onjia, Antonije
AU  - Čokeša, Đuro
AU  - Čupić, Svetlana
AU  - Tašić, Žaklina
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7216
PB  - Beograd : Poslovna zajednica Vrenje
C3  - Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god
T1  - Determination of metals in food dyes by means of ICP-AES, GF-AAS, and EDXRF
EP  - 61
SP  - 57
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7216
ER  - 

@conference{
author = "Onjia, Antonije and Čokeša, Đuro and Čupić, Svetlana and Tašić, Žaklina",
year = "2000",
publisher = "Beograd : Poslovna zajednica Vrenje",
journal = "Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god",
title = "Determination of metals in food dyes by means of ICP-AES, GF-AAS, and EDXRF",
pages = "61-57",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7216"
}

Onjia, A., Čokeša, Đ., Čupić, S.,& Tašić, Ž.. (2000). Determination of metals in food dyes by means of ICP-AES, GF-AAS, and EDXRF. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god
Beograd : Poslovna zajednica Vrenje., 57-61.
https://hdl.handle.net/21.15107/rcub_technorep_7216

Onjia A, Čokeša Đ, Čupić S, Tašić Ž. Determination of metals in food dyes by means of ICP-AES, GF-AAS, and EDXRF. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god. 2000;:57-61.
https://hdl.handle.net/21.15107/rcub_technorep_7216 .

Onjia, Antonije, Čokeša, Đuro, Čupić, Svetlana, Tašić, Žaklina, "Determination of metals in food dyes by means of ICP-AES, GF-AAS, and EDXRF" in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god (2000):57-61,
https://hdl.handle.net/21.15107/rcub_technorep_7216 .

TY  - CONF
AU  - Tašić, Žaklina
AU  - Čupić, Svetlana
AU  - Čokeša, Đuro
AU  - Onjia, Antonije
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7217
PB  - Beograd : Poslovna zajednica Vrenje
C3  - Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god
T1  - Identification and quantification of synthetic food dyes in drinks by HPLC
EP  - 67
SP  - 63
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7217
ER  - 

@conference{
author = "Tašić, Žaklina and Čupić, Svetlana and Čokeša, Đuro and Onjia, Antonije",
year = "2000",
publisher = "Beograd : Poslovna zajednica Vrenje",
journal = "Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god",
title = "Identification and quantification of synthetic food dyes in drinks by HPLC",
pages = "67-63",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7217"
}

Tašić, Ž., Čupić, S., Čokeša, Đ.,& Onjia, A.. (2000). Identification and quantification of synthetic food dyes in drinks by HPLC. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god
Beograd : Poslovna zajednica Vrenje., 63-67.
https://hdl.handle.net/21.15107/rcub_technorep_7217

Tašić Ž, Čupić S, Čokeša Đ, Onjia A. Identification and quantification of synthetic food dyes in drinks by HPLC. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god. 2000;:63-67.
https://hdl.handle.net/21.15107/rcub_technorep_7217 .

Tašić, Žaklina, Čupić, Svetlana, Čokeša, Đuro, Onjia, Antonije, "Identification and quantification of synthetic food dyes in drinks by HPLC" in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja, 4-7. juni 2000. god (2000):63-67,
https://hdl.handle.net/21.15107/rcub_technorep_7217 .

TY  - CONF
AU  - Tašić, Žaklina
AU  - Čupić, Svetlana
AU  - Čokeša, Đuro
AU  - Onjia, Antonije
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7201
PB  - Beograd : Poslovna zajednica Vrenje
C3  - Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja 4-7 juni 2000. god.
T1  - Identifikacija i kvantifikacija veštačkih boja u pićima metodom HPLC
EP  - 67
SP  - 63
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7201
ER  - 

@conference{
author = "Tašić, Žaklina and Čupić, Svetlana and Čokeša, Đuro and Onjia, Antonije",
year = "2000",
publisher = "Beograd : Poslovna zajednica Vrenje",
journal = "Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja 4-7 juni 2000. god.",
title = "Identifikacija i kvantifikacija veštačkih boja u pićima metodom HPLC",
pages = "67-63",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7201"
}

Tašić, Ž., Čupić, S., Čokeša, Đ.,& Onjia, A.. (2000). Identifikacija i kvantifikacija veštačkih boja u pićima metodom HPLC. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja 4-7 juni 2000. god.
Beograd : Poslovna zajednica Vrenje., 63-67.
https://hdl.handle.net/21.15107/rcub_technorep_7201

Tašić Ž, Čupić S, Čokeša Đ, Onjia A. Identifikacija i kvantifikacija veštačkih boja u pićima metodom HPLC. in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja 4-7 juni 2000. god.. 2000;:63-67.
https://hdl.handle.net/21.15107/rcub_technorep_7201 .

Tašić, Žaklina, Čupić, Svetlana, Čokeša, Đuro, Onjia, Antonije, "Identifikacija i kvantifikacija veštačkih boja u pićima metodom HPLC" in Zbornik radova / V savetovanje industrije alkoholnih i bezalkoholnih pića i sirćeta sa međunarodnim učešćem, Vrnjačka Banja 4-7 juni 2000. god. (2000):63-67,
https://hdl.handle.net/21.15107/rcub_technorep_7201 .

TY  - CONF
AU  - Onjia, Antonije
AU  - Iđaković, Zoja
AU  - Čupić, Svetlana
AU  - Čokeša, Đuro
PY  - 1999
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7239
PB  - Beograd : Srpsko hemijsko društvo
C3  - Knjiga izvoda / 12. jugoslovensko savetovanje o opštoj i primenjenoj spektroskopiji, sa međunarodnim učešćem, Beograd, 25-27. oktobar 1999. godine
T1  - Kombinacija tečne hromatografije i spektroskopskih metoda za analizu mankozeba u malinama
T1  - Analysis of Mancozeb in Raspberry by HPLC-ICP-AES
EP  - 36
SP  - 35
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7239
ER  - 

@conference{
author = "Onjia, Antonije and Iđaković, Zoja and Čupić, Svetlana and Čokeša, Đuro",
year = "1999",
publisher = "Beograd : Srpsko hemijsko društvo",
journal = "Knjiga izvoda / 12. jugoslovensko savetovanje o opštoj i primenjenoj spektroskopiji, sa međunarodnim učešćem, Beograd, 25-27. oktobar 1999. godine",
title = "Kombinacija tečne hromatografije i spektroskopskih metoda za analizu mankozeba u malinama, Analysis of Mancozeb in Raspberry by HPLC-ICP-AES",
pages = "36-35",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7239"
}

Onjia, A., Iđaković, Z., Čupić, S.,& Čokeša, Đ.. (1999). Kombinacija tečne hromatografije i spektroskopskih metoda za analizu mankozeba u malinama. in Knjiga izvoda / 12. jugoslovensko savetovanje o opštoj i primenjenoj spektroskopiji, sa međunarodnim učešćem, Beograd, 25-27. oktobar 1999. godine
Beograd : Srpsko hemijsko društvo., 35-36.
https://hdl.handle.net/21.15107/rcub_technorep_7239

Onjia A, Iđaković Z, Čupić S, Čokeša Đ. Kombinacija tečne hromatografije i spektroskopskih metoda za analizu mankozeba u malinama. in Knjiga izvoda / 12. jugoslovensko savetovanje o opštoj i primenjenoj spektroskopiji, sa međunarodnim učešćem, Beograd, 25-27. oktobar 1999. godine. 1999;:35-36.
https://hdl.handle.net/21.15107/rcub_technorep_7239 .

Onjia, Antonije, Iđaković, Zoja, Čupić, Svetlana, Čokeša, Đuro, "Kombinacija tečne hromatografije i spektroskopskih metoda za analizu mankozeba u malinama" in Knjiga izvoda / 12. jugoslovensko savetovanje o opštoj i primenjenoj spektroskopiji, sa međunarodnim učešćem, Beograd, 25-27. oktobar 1999. godine (1999):35-36,
https://hdl.handle.net/21.15107/rcub_technorep_7239 .

TY  - JOUR
AU  - Onjia, Antonije
AU  - Čokeša, Đuro
AU  - Janković, Ivana
AU  - Milonjić, Slobodan K.
PY  - 1998
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7222
AB  - U radu je data jedna brza i jednostavna metoda visoko-efikasne tečne
hromatografije (HPLC) za analizu sadržaja sredstva otpornog na insekte bematina
987 na vuni. Bematin 987 koji sadrži cis- i trans-permetrin kao activne ingredijente
ekstahovan je smešom rastvarača heksan-metilen hlorid-aceton u ultazučnoj kadi i
hromatografisan bez prečišćavanja ekstrakta. Detekcija je vršena pomoću UV/Vis
detektora na  = 220 nm, posle razdvajanja na reverzno-faznoj C18 koloni. Prosečan
prinos analitičkog postupka i relativna standardna devijacija za različite nivoe
opterećenja uzoraka bematinom su 85% i 8%. Detekcioni limit metode je 0.01 %
v/w.
AB  - In the paper a rapid and simple high-performance liquid chromatography
(HPLC) assay for analysis of content of insect resist agent bematin 987 on wool
was presented. Bematin 987 containing cis- and trans-permethrin as active
ingredients was extracted with hexane-metilen chloride-acetone solvent mixture in
a ultrasonic bath and chromatographed without clean-up. Detection was done by
means of UV/Vis detector at    nm, after separation on a reversed-phase C18
column. Mean recovery and relative standard deviation for different fortification
level of bematin 987 were 85% and 8%, respectively. Method detection limit is
0.01 % v/w.
PB  - Viskoza
T2  - Hemijska vlakna
T1  - Određivanje sadržaja sredstva za obradu protiv insekata bematin 987 na vuni metodom visoko-efikasne tečne hromatografije
T1  - Determination of Content of Insect Resist Agent Bematin 987 on Wool by High-Performance Liquid Chromatography
EP  - 24
IS  - 1-4
SP  - 22
VL  - 38
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7222
ER  - 

@article{
author = "Onjia, Antonije and Čokeša, Đuro and Janković, Ivana and Milonjić, Slobodan K.",
year = "1998",
abstract = "U radu je data jedna brza i jednostavna metoda visoko-efikasne tečne
hromatografije (HPLC) za analizu sadržaja sredstva otpornog na insekte bematina
987 na vuni. Bematin 987 koji sadrži cis- i trans-permetrin kao activne ingredijente
ekstahovan je smešom rastvarača heksan-metilen hlorid-aceton u ultazučnoj kadi i
hromatografisan bez prečišćavanja ekstrakta. Detekcija je vršena pomoću UV/Vis
detektora na  = 220 nm, posle razdvajanja na reverzno-faznoj C18 koloni. Prosečan
prinos analitičkog postupka i relativna standardna devijacija za različite nivoe
opterećenja uzoraka bematinom su 85% i 8%. Detekcioni limit metode je 0.01 %
v/w., In the paper a rapid and simple high-performance liquid chromatography
(HPLC) assay for analysis of content of insect resist agent bematin 987 on wool
was presented. Bematin 987 containing cis- and trans-permethrin as active
ingredients was extracted with hexane-metilen chloride-acetone solvent mixture in
a ultrasonic bath and chromatographed without clean-up. Detection was done by
means of UV/Vis detector at    nm, after separation on a reversed-phase C18
column. Mean recovery and relative standard deviation for different fortification
level of bematin 987 were 85% and 8%, respectively. Method detection limit is
0.01 % v/w.",
publisher = "Viskoza",
journal = "Hemijska vlakna",
title = "Određivanje sadržaja sredstva za obradu protiv insekata bematin 987 na vuni metodom visoko-efikasne tečne hromatografije, Determination of Content of Insect Resist Agent Bematin 987 on Wool by High-Performance Liquid Chromatography",
pages = "24-22",
number = "1-4",
volume = "38",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7222"
}

Onjia, A., Čokeša, Đ., Janković, I.,& Milonjić, S. K.. (1998). Određivanje sadržaja sredstva za obradu protiv insekata bematin 987 na vuni metodom visoko-efikasne tečne hromatografije. in Hemijska vlakna
Viskoza., 38(1-4), 22-24.
https://hdl.handle.net/21.15107/rcub_technorep_7222

Onjia A, Čokeša Đ, Janković I, Milonjić SK. Određivanje sadržaja sredstva za obradu protiv insekata bematin 987 na vuni metodom visoko-efikasne tečne hromatografije. in Hemijska vlakna. 1998;38(1-4):22-24.
https://hdl.handle.net/21.15107/rcub_technorep_7222 .

Onjia, Antonije, Čokeša, Đuro, Janković, Ivana, Milonjić, Slobodan K., "Određivanje sadržaja sredstva za obradu protiv insekata bematin 987 na vuni metodom visoko-efikasne tečne hromatografije" in Hemijska vlakna, 38, no. 1-4 (1998):22-24,
https://hdl.handle.net/21.15107/rcub_technorep_7222 .