TY  - JOUR
AU  - Ražić, Slavica
AU  - Bakić, Tamara
AU  - Topić, Aleksandra
AU  - Lukić, Jelena
AU  - Onjia, Antonije
PY  - 2023
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/4549
AB  - A fast and straightforward reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) using a deep eutectic solvent (DES) procedure to determine free tryptophan in vegetable oils was developed. The influence of eight variables affecting the RP-DLLME efficiency has been studied by a multivariate approach. A Plackett–Burman design for screening the most influential variables followed by a central composite response surface methodology led to an optimum RP-DLLME setup for a 1 g oil sample: 9 mL hexane as the diluting solvent, vortex extraction with 0.45 mL of DES (choline chloride–urea) at 40 °C, without addition of salt, and centrifugation at 6000 rpm for 4.0 min. The reconstituted extract was directly injected into a high-performance liquid chromatography (HPLC) system working in the diode array mode. At the studied concentration levels, the obtained method detection limits (MDL) was 11 mg/kg, linearity in matrix-matched standards was R2 ≥ 0.997, relative standard deviations (RSD) was 7.8%, and average recovery was 93%. The combined use of the recently developed DES -based RP-DLLME and HPLC provides an innovative, efficient, cost-effective, and more sustainable method for the extraction and quantification of free tryptophan in oily food matrices. The method was employed to analyze cold-pressed oils from nine vegetables (Brazil nut, almond, cashew, hazelnut, peanut, pumpkin, sesame, sunflower, and walnut) for the first time. The results showed that free tryptophan was present in the range of 11–38 mg/100 g. This article is important for its contributions to the field of food analysis, and for its development of a new and efficient method for the determination of free tryptophan in complex matrices, which has the potential to be applied to other analytes and sample types.
PB  - MDPI
T2  - Molecules
T1  - Deep Eutectic Solvent Based Reversed-Phase Dispersive Liquid–Liquid Microextraction and High-Performance Liquid Chromatography for the Determination of Free Tryptophan in Cold-Pressed Oils
VL  - 28
IS  - 5
DO  - 10.3390/molecules28052395
ER  - 

@article{
author = "Ražić, Slavica and Bakić, Tamara and Topić, Aleksandra and Lukić, Jelena and Onjia, Antonije",
year = "2023",
abstract = "A fast and straightforward reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) using a deep eutectic solvent (DES) procedure to determine free tryptophan in vegetable oils was developed. The influence of eight variables affecting the RP-DLLME efficiency has been studied by a multivariate approach. A Plackett–Burman design for screening the most influential variables followed by a central composite response surface methodology led to an optimum RP-DLLME setup for a 1 g oil sample: 9 mL hexane as the diluting solvent, vortex extraction with 0.45 mL of DES (choline chloride–urea) at 40 °C, without addition of salt, and centrifugation at 6000 rpm for 4.0 min. The reconstituted extract was directly injected into a high-performance liquid chromatography (HPLC) system working in the diode array mode. At the studied concentration levels, the obtained method detection limits (MDL) was 11 mg/kg, linearity in matrix-matched standards was R2 ≥ 0.997, relative standard deviations (RSD) was 7.8%, and average recovery was 93%. The combined use of the recently developed DES -based RP-DLLME and HPLC provides an innovative, efficient, cost-effective, and more sustainable method for the extraction and quantification of free tryptophan in oily food matrices. The method was employed to analyze cold-pressed oils from nine vegetables (Brazil nut, almond, cashew, hazelnut, peanut, pumpkin, sesame, sunflower, and walnut) for the first time. The results showed that free tryptophan was present in the range of 11–38 mg/100 g. This article is important for its contributions to the field of food analysis, and for its development of a new and efficient method for the determination of free tryptophan in complex matrices, which has the potential to be applied to other analytes and sample types.",
publisher = "MDPI",
journal = "Molecules",
title = "Deep Eutectic Solvent Based Reversed-Phase Dispersive Liquid–Liquid Microextraction and High-Performance Liquid Chromatography for the Determination of Free Tryptophan in Cold-Pressed Oils",
volume = "28",
number = "5",
doi = "10.3390/molecules28052395"
}

Ražić, S., Bakić, T., Topić, A., Lukić, J.,& Onjia, A.. (2023). Deep Eutectic Solvent Based Reversed-Phase Dispersive Liquid–Liquid Microextraction and High-Performance Liquid Chromatography for the Determination of Free Tryptophan in Cold-Pressed Oils. in Molecules
MDPI., 28(5).
https://doi.org/10.3390/molecules28052395

Ražić S, Bakić T, Topić A, Lukić J, Onjia A. Deep Eutectic Solvent Based Reversed-Phase Dispersive Liquid–Liquid Microextraction and High-Performance Liquid Chromatography for the Determination of Free Tryptophan in Cold-Pressed Oils. in Molecules. 2023;28(5).
doi:10.3390/molecules28052395 .

Ražić, Slavica, Bakić, Tamara, Topić, Aleksandra, Lukić, Jelena, Onjia, Antonije, "Deep Eutectic Solvent Based Reversed-Phase Dispersive Liquid–Liquid Microextraction and High-Performance Liquid Chromatography for the Determination of Free Tryptophan in Cold-Pressed Oils" in Molecules, 28, no. 5 (2023),
https://doi.org/10.3390/molecules28052395 . .

TY  - JOUR
AU  - Krstić, Marko
AU  - Maksimović, Zoran
AU  - Ibrić, Svetlana
AU  - Bakić, Tamara
AU  - Prodanović, Jovana
AU  - Ražić, Slavica
PY  - 2018
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3137
AB  - In this paper, agricultural waste (corn stover and wheat straw) was used for isolation of microcrystalline cellulose (MCC). Lignocellulosic biomass is widely available and applying smart technologies to valorise it will have a double benefit through environmental protection and achieving high-performance materials for targeted applications. The obtained MCC showed excellent features in terms of purity, physical-chemical properties and safety, as well. The methods applied for characterizing the materials were as follows: FT-IR, SEM, ICP-AAE and IC. Then, tablets were made by the compression method, using the isolated and purified MCC, as well as its commercially available counterpart. Excellent technological characteristics were confirmed by testing material compaction, compactibility, compressibility and drug release. This was one of the first tests in which Gamlen Tableting D was applied, especially in the case of using biomass, in the first phase, with prospects of application at a large scale, particularly, in the pharmaceutical industry.
PB  - Editura Acad Romane, Bucuresti
T2  - Cellulose Chemistry and Technology
T1  - Lignocellulosic biomass as a source of microcrystalline cellulose - chemical and technological characterization and future perspectives
VL  - 52
IS  - 7-8
SP  - 577
EP  - 588
UR  - https://hdl.handle.net/21.15107/rcub_farfar_3137
ER  - 

@article{
author = "Krstić, Marko and Maksimović, Zoran and Ibrić, Svetlana and Bakić, Tamara and Prodanović, Jovana and Ražić, Slavica",
year = "2018",
abstract = "In this paper, agricultural waste (corn stover and wheat straw) was used for isolation of microcrystalline cellulose (MCC). Lignocellulosic biomass is widely available and applying smart technologies to valorise it will have a double benefit through environmental protection and achieving high-performance materials for targeted applications. The obtained MCC showed excellent features in terms of purity, physical-chemical properties and safety, as well. The methods applied for characterizing the materials were as follows: FT-IR, SEM, ICP-AAE and IC. Then, tablets were made by the compression method, using the isolated and purified MCC, as well as its commercially available counterpart. Excellent technological characteristics were confirmed by testing material compaction, compactibility, compressibility and drug release. This was one of the first tests in which Gamlen Tableting D was applied, especially in the case of using biomass, in the first phase, with prospects of application at a large scale, particularly, in the pharmaceutical industry.",
publisher = "Editura Acad Romane, Bucuresti",
journal = "Cellulose Chemistry and Technology",
title = "Lignocellulosic biomass as a source of microcrystalline cellulose - chemical and technological characterization and future perspectives",
volume = "52",
number = "7-8",
pages = "577-588",
url = "https://hdl.handle.net/21.15107/rcub_farfar_3137"
}

Krstić, M., Maksimović, Z., Ibrić, S., Bakić, T., Prodanović, J.,& Ražić, S.. (2018). Lignocellulosic biomass as a source of microcrystalline cellulose - chemical and technological characterization and future perspectives. in Cellulose Chemistry and Technology
Editura Acad Romane, Bucuresti., 52(7-8), 577-588.
https://hdl.handle.net/21.15107/rcub_farfar_3137

Krstić M, Maksimović Z, Ibrić S, Bakić T, Prodanović J, Ražić S. Lignocellulosic biomass as a source of microcrystalline cellulose - chemical and technological characterization and future perspectives. in Cellulose Chemistry and Technology. 2018;52(7-8):577-588.
https://hdl.handle.net/21.15107/rcub_farfar_3137 .

Krstić, Marko, Maksimović, Zoran, Ibrić, Svetlana, Bakić, Tamara, Prodanović, Jovana, Ražić, Slavica, "Lignocellulosic biomass as a source of microcrystalline cellulose - chemical and technological characterization and future perspectives" in Cellulose Chemistry and Technology, 52, no. 7-8 (2018):577-588,
https://hdl.handle.net/21.15107/rcub_farfar_3137 .