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Nowadays, the interest in preparing new, cheap and simple adsorbents that are used in sample preparation is on the rise. Graphene oxide (GO) nanomaterials and nanocomposites have become increasingly popular due to the novel methods of syntheses that have been published. Owing to their vast specific surface area and their π-delocalized electron system they possess, they are appropriate for the adsorption of a variety of aromatic organic compounds, being utilized either as adsorbents in analytical methods or as filter materials for the removal of pollutants in water. Pharmaceutical compounds, such as benzodiazepines, end up in surface waters caused by consumption or their disposal through sewage, thus becoming pollutants. In the present study, an analytical method has been developed and validated for the determination of two model-analytes of benzodiazepines by HPLC-DAD and their sample preparation protocol which consists of the Stir bar magnetic solid phase extraction (SB-MSPE) method, evaluating therefore the nanocomposite material as a decent adsorbent. The separation took place with the usage of an analytical column C18 RP-HPLC in 10 min. For the alprazolam (ALP) and the flunitrazepam (FLT), the LODs and LOQs were 3 ng/mL and 10 ng/mL, respectively, while the relative recoveries ranged between 93.6–112.9% and the RSDs were 1.11–9.50%. Finally, the material was examined for its reusability and was found that it can be used for over eight cycles of extraction/elution.
Orfeas-Evangelos Plastiras; Eleni Deliyanni; Victoria Samanidou. Synthesis and Application of the Magnetic Nanocomposite GO-Chm for the Extraction of Benzodiazepines from Surface Water Samples Prior to HPLC-PDA Analysis. Applied Sciences 2021, 11, 7828 .
AMA StyleOrfeas-Evangelos Plastiras, Eleni Deliyanni, Victoria Samanidou. Synthesis and Application of the Magnetic Nanocomposite GO-Chm for the Extraction of Benzodiazepines from Surface Water Samples Prior to HPLC-PDA Analysis. Applied Sciences. 2021; 11 (17):7828.
Chicago/Turabian StyleOrfeas-Evangelos Plastiras; Eleni Deliyanni; Victoria Samanidou. 2021. "Synthesis and Application of the Magnetic Nanocomposite GO-Chm for the Extraction of Benzodiazepines from Surface Water Samples Prior to HPLC-PDA Analysis." Applied Sciences 11, no. 17: 7828.
In recent years, there has been an increase in public perception of the detrimental side-effects of fluoride to human health due to its effects on teeth and bones. Today, there is a plethora of techniques available for the removal of fluoride from drinking water. Among them, adsorption is a very prospective method because of its handy operation, cost efficiency, and high selectivity. Along with efforts to assist fluoride removal from drinking waters, extensive attention has been also paid to the accurate measurement of fluoride in water. Currently, the analytical methods that are used for fluoride determination can be classified into chromatographic methods (e.g., ionic chromatography), electrochemical methods (e.g., voltammetry, potentiometry, and polarography), spectroscopic methods (e.g., molecular absorption spectrometry), microfluidic analysis (e.g., flow injection analysis and sequential injection analysis), titration, and sensors. In this review article, we discuss the available techniques and the ongoing effort for achieving enhanced fluoride removal by applying novel adsorbents such as carbon-based materials (i.e., activated carbon, graphene oxide, and carbon nanotubes) and nanostructured materials, combining metals and their oxides or hydroxides as well as natural materials. Emphasis has been given to the use of lanthanum (La) in the modification of materials, both activated carbon and hybrid materials (i.e., La/Mg/Si-AC, La/MA, LaFeO3 NPs), and in the use of MgO nanostructures, which are found to exhibit an adsorption capacity of up to 29,131 mg g−1. The existing analytical methodologies and the current trends in analytical chemistry for fluoride determination in drinking water are also discussed.
Athanasia Tolkou; Natalia Manousi; George Zachariadis; Ioannis Katsoyiannis; Eleni Deliyanni. Recently Developed Adsorbing Materials for Fluoride Removal from Water and Fluoride Analytical Determination Techniques: A Review. Sustainability 2021, 13, 7061 .
AMA StyleAthanasia Tolkou, Natalia Manousi, George Zachariadis, Ioannis Katsoyiannis, Eleni Deliyanni. Recently Developed Adsorbing Materials for Fluoride Removal from Water and Fluoride Analytical Determination Techniques: A Review. Sustainability. 2021; 13 (13):7061.
Chicago/Turabian StyleAthanasia Tolkou; Natalia Manousi; George Zachariadis; Ioannis Katsoyiannis; Eleni Deliyanni. 2021. "Recently Developed Adsorbing Materials for Fluoride Removal from Water and Fluoride Analytical Determination Techniques: A Review." Sustainability 13, no. 13: 7061.
Bioanalysis is the scientific field of the quantitative determination of xenobiotics (e.g., drugs and their metabolites) and biotics (e.g., macromolecules) in biological matrices. The most common samples in bioanalysis include blood (i.e., serum, plasma and whole blood) and urine. However, the analysis of alternative biosamples, such as hair and nails are gaining more and more attention. The main limitations for the determination of small organic compounds in biological samples is their low concentration in these matrices, in combination with the sample complexity. Therefore, a sample preparation/analyte preconcentration step is typically required. Currently, the development of novel microextraction and miniaturized extraction techniques, as well as novel adsorbents for the analysis of biosamples, in compliance with the requirements of Green Analytical Chemistry, is in the forefront of research in analytical chemistry. Graphene oxide (GO) is undoubtedly a powerful adsorbent for sample preparation that has been successfully coupled with a plethora of green extraction techniques. GO is composed of carbon atoms in a sp2 single-atom layer of a hybrid connection, and it exhibits high surface area, as well as good mechanical and thermal stability. In this review, we aim to discuss the applications of GO and functionalized GO derivatives in microextraction and miniaturized extraction techniques for the determination of small organic molecules in biological samples.
Natalia Manousi; Orfeas-Evangelos Plastiras; Eleni Deliyanni; George Zachariadis. Green Bioanalytical Applications of Graphene Oxide for the Extraction of Small Organic Molecules. Molecules 2021, 26, 2790 .
AMA StyleNatalia Manousi, Orfeas-Evangelos Plastiras, Eleni Deliyanni, George Zachariadis. Green Bioanalytical Applications of Graphene Oxide for the Extraction of Small Organic Molecules. Molecules. 2021; 26 (9):2790.
Chicago/Turabian StyleNatalia Manousi; Orfeas-Evangelos Plastiras; Eleni Deliyanni; George Zachariadis. 2021. "Green Bioanalytical Applications of Graphene Oxide for the Extraction of Small Organic Molecules." Molecules 26, no. 9: 2790.
Thiophenic compounds constitute a class of sulfur compounds derived by thiophene, containing at least one thiophenic ring. Their presence in fuels (crude oil, etc.) is important and can reach 3% m/m. The combustion of fuels leads to the formation of sulfur oxides a severe source of environmental pollution issues, such as acid rain with adverse effects both to humans and to the environment. To reduce such problems, the EU and other regulatory agencies worldwide set increasingly stringent regulations for sulfur content in fuels resulting in the necessity for intense desulphurization processes. However, most of these processes are inefficient in the total removal of sulfur compounds. Therefore, thiophenic compounds such as benzothiophenes and dibenzothiophenes are still present in heavier fractions of petroleum, therefore, their determination is of great importance. Until now, all HPLC methods applied in similar studies use gradient elution programs that may last more than 25 min with no validation results provided. To fill this gap, the aim of the present study was to develop and validate a simple and fast HPLC-UV method in order to be used as a useful monitoring tool in the evaluation studies of novel desulfurization technologies by means of simultaneous determination of dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene and dibenzothiophene sulfone in the desulfurization effluents.
Vasiliki Kapsali; Konstantinos Triantafyllidis; Eleni Deliyanni; Victoria Samanidou. Monitoring of Remaining Thiophenic Compounds in Liquid Fuel Desulphurization Studies Using a Fast HPLC-UV Method. Separations 2021, 8, 48 .
AMA StyleVasiliki Kapsali, Konstantinos Triantafyllidis, Eleni Deliyanni, Victoria Samanidou. Monitoring of Remaining Thiophenic Compounds in Liquid Fuel Desulphurization Studies Using a Fast HPLC-UV Method. Separations. 2021; 8 (4):48.
Chicago/Turabian StyleVasiliki Kapsali; Konstantinos Triantafyllidis; Eleni Deliyanni; Victoria Samanidou. 2021. "Monitoring of Remaining Thiophenic Compounds in Liquid Fuel Desulphurization Studies Using a Fast HPLC-UV Method." Separations 8, no. 4: 48.
Sample preparation is an essential and preliminary procedure of most chemical analyses. Due to the sample diversity, the selection of appropriate adsorbents for the effective preparation and separation of different samples turned out to be important for the methods. By exploiting the rapid development of material science, some novel adsorption materials, especially graphene-based nanomaterials, have shown supremacy in sample pretreatment. In this review, a discussion between these nanomaterials will be made, as well as some basic information about their synthesis. The focus will be on the different environmental applications that use these materials.
Orfeas-Evangelos Plastiras; Eleni Deliyanni; Victoria Samanidou. Applications of Graphene-Based Nanomaterials in Environmental Analysis. Applied Sciences 2021, 11, 3028 .
AMA StyleOrfeas-Evangelos Plastiras, Eleni Deliyanni, Victoria Samanidou. Applications of Graphene-Based Nanomaterials in Environmental Analysis. Applied Sciences. 2021; 11 (7):3028.
Chicago/Turabian StyleOrfeas-Evangelos Plastiras; Eleni Deliyanni; Victoria Samanidou. 2021. "Applications of Graphene-Based Nanomaterials in Environmental Analysis." Applied Sciences 11, no. 7: 3028.
A novel graphene-oxide-derived material was synthesized after modification of graphene oxide with sodium hydroxide and used for the dispersive solid-phase extraction (d-SPE) of different elements (Pb, Cd, Ba, Zn, Cu and Ni) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The prepared nanomaterial was characterized by X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Full factorial design and Derringer’s type desirability function were used for the optimization of the d-SPE procedure. Pareto charts illustrated the effects of each of the examined factors and their interactions on the determination of the elements. Under the optimum conditions, detection limits (LODs) for the elements ranged between 0.01 and 0.21 μg g−1, intra-day repeatability (n = 5) was lower than 1.9% and inter-day repeatability (n = 5 × 3) was lower than 4.7%. Relative recovery values ranged between 88.1 and 117.8%. The method was validated and successfully applied for the determination of trace elements in poultry, pork and beef samples from the local market. The proposed method is simple, rapid, sensitive and the novel sorbent can be used at least ten times.
Natalia Manousi; Eleni Deliyanni; George Zachariadis. Multi-Element Determination of Toxic and Nutrient Elements by ICP-AES after Dispersive Solid-Phase Extraction with Modified Graphene Oxide. Applied Sciences 2020, 10, 8722 .
AMA StyleNatalia Manousi, Eleni Deliyanni, George Zachariadis. Multi-Element Determination of Toxic and Nutrient Elements by ICP-AES after Dispersive Solid-Phase Extraction with Modified Graphene Oxide. Applied Sciences. 2020; 10 (23):8722.
Chicago/Turabian StyleNatalia Manousi; Eleni Deliyanni; George Zachariadis. 2020. "Multi-Element Determination of Toxic and Nutrient Elements by ICP-AES after Dispersive Solid-Phase Extraction with Modified Graphene Oxide." Applied Sciences 10, no. 23: 8722.
Graphene oxide is a compound with a form similar to graphene, composed of carbon atoms in a sp2 single-atom layer of a hybrid connection. Due to its significant surface area and its good mechanical and thermal stability, graphene oxide has a plethora of applications in various scientific fields including heterogenous catalysis, gas storage, environmental remediation, etc. In analytical chemistry, graphene oxide has been successfully employed for the extraction and preconcentration of organic compounds, metal ions, and proteins. Since graphene oxide sheets are negatively charged in aqueous solutions, the material and its derivatives are ideal sorbents to bind with metal ions. To date, various graphene oxide nanocomposites have been successfully synthesized and evaluated for the extraction and preconcentration of metal ions from biological, environmental, agricultural, and food samples. In this review article, we aim to discuss the application of graphene oxide and functionalized graphene oxide nanocomposites for the extraction of metal ions prior to their determination via an instrumental analytical technique. Applications of ionic liquids and deep eutectic solvents for the modification of graphene oxide and its functionalized derivatives are also discussed.
Natalia Manousi; Erwin Rosenberg; Eleni A. Deliyanni; George A. Zachariadis. Sample Preparation Using Graphene-Oxide-Derived Nanomaterials for the Extraction of Metals. Molecules 2020, 25, 2411 .
AMA StyleNatalia Manousi, Erwin Rosenberg, Eleni A. Deliyanni, George A. Zachariadis. Sample Preparation Using Graphene-Oxide-Derived Nanomaterials for the Extraction of Metals. Molecules. 2020; 25 (10):2411.
Chicago/Turabian StyleNatalia Manousi; Erwin Rosenberg; Eleni A. Deliyanni; George A. Zachariadis. 2020. "Sample Preparation Using Graphene-Oxide-Derived Nanomaterials for the Extraction of Metals." Molecules 25, no. 10: 2411.
Adsorption of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) from solutions in hexane and hexadecane respectively as well as in acetonitrile for both thiophenic compounds was investigated with sorbents of three activated carbons and their oxidized counterparts. The raw sorbents were of different surface acidity. Oxygen surface groups created after oxidation increased the adsorption of thiophenic compounds via polar interactions.
Kyriazis Rekos; Zoi-Christina Kampouraki; Chrisowalantou Panou; Alexandra Baspanelou; Konstantinos Triantafyllidis; Eleni Deliyanni. Adsorption of DBT and 4,6-DMDBTon nanoporous activated carbons: the role of surface chemistry and the solvent. Environmental Science and Pollution Research 2020, 1 -13.
AMA StyleKyriazis Rekos, Zoi-Christina Kampouraki, Chrisowalantou Panou, Alexandra Baspanelou, Konstantinos Triantafyllidis, Eleni Deliyanni. Adsorption of DBT and 4,6-DMDBTon nanoporous activated carbons: the role of surface chemistry and the solvent. Environmental Science and Pollution Research. 2020; ():1-13.
Chicago/Turabian StyleKyriazis Rekos; Zoi-Christina Kampouraki; Chrisowalantou Panou; Alexandra Baspanelou; Konstantinos Triantafyllidis; Eleni Deliyanni. 2020. "Adsorption of DBT and 4,6-DMDBTon nanoporous activated carbons: the role of surface chemistry and the solvent." Environmental Science and Pollution Research , no. : 1-13.
Graphene oxide (GO) is a chemical compound with a form similar to graphene that consists of one-atom-thick two-dimensional layers of sp2-bonded carbon. Graphene oxide exhibits high hydrophilicity and dispersibility. Thus, it is difficult to be separated from aqueous solutions. Therefore, functionalization with magnetic nanoparticles is performed in order to prepare a magnetic GO nanocomposite that combines the sufficient adsorption capacity of graphene oxide and the convenience of magnetic separation. Moreover, the magnetic material can be further functionalized with different groups to prevent aggregation and extends its potential application. Until today, a plethora of magnetic GO hybrid materials have been synthesized and successfully employed for the magnetic solid-phase extraction of organic compounds from environmental, agricultural, biological, and food samples. The developed GO nanocomposites exhibit satisfactory stability in aqueous solutions, as well as sufficient surface area. Thus, they are considered as an alternative to conventional sorbents by enriching the analytical toolbox for the analysis of trace organic compounds.
Natalia Manousi; Erwin Rosenberg; Eleni Deliyanni; George A. Zachariadis; Victoria Samanidou. Magnetic Solid-Phase Extraction of Organic Compounds Based on Graphene Oxide Nanocomposites. Molecules 2020, 25, 1148 .
AMA StyleNatalia Manousi, Erwin Rosenberg, Eleni Deliyanni, George A. Zachariadis, Victoria Samanidou. Magnetic Solid-Phase Extraction of Organic Compounds Based on Graphene Oxide Nanocomposites. Molecules. 2020; 25 (5):1148.
Chicago/Turabian StyleNatalia Manousi; Erwin Rosenberg; Eleni Deliyanni; George A. Zachariadis; Victoria Samanidou. 2020. "Magnetic Solid-Phase Extraction of Organic Compounds Based on Graphene Oxide Nanocomposites." Molecules 25, no. 5: 1148.
The concept of metal–organic frameworks (MOFs) was first introduced in 1990; nowadays they are among the most promising novel materials
Victoria F. Samanidou; Eleni A. Deliyanni. Metal Organic Frameworks: Synthesis and Application. Molecules 2020, 25, 960 .
AMA StyleVictoria F. Samanidou, Eleni A. Deliyanni. Metal Organic Frameworks: Synthesis and Application. Molecules. 2020; 25 (4):960.
Chicago/Turabian StyleVictoria F. Samanidou; Eleni A. Deliyanni. 2020. "Metal Organic Frameworks: Synthesis and Application." Molecules 25, no. 4: 960.
Ultradeep desulfurization of fuels is a method of enormous demand due to the generation of harmful compounds during the burning of sulfur-containing fuels, which are a major source of environmental pollution. Among the various desulfurization methods in application, adsorptive desulfurization (ADS) has low energy demand and is feasible to be employed at ambient conditions without the addition of chemicals. The most crucial factor for ADS application is the selection of the adsorbent, and, currently, a new family of porous materials, metal organic frameworks (MOFs), has proved to be very effective towards this direction. In the current review, applications of MOFs and their functionalized composites for ADS are presented and discussed, as well as the main desulfurization mechanisms reported for the removal of thiophenic compounds by various frameworks. Prospective methods regarding the further improvement of MOF’s desulfurization capability are also suggested.
Zoi Christina Kampouraki; Dimitrios A. Giannakoudakis; Vaishakh Nair; Ahmad Hosseini-Bandegharaei; Juan Carlos Colmenares; Eleni A. Deliyanni. Metal Organic Frameworks as Desulfurization Adsorbents of DBT and 4,6-DMDBT from Fuels. Molecules 2019, 24, 4525 .
AMA StyleZoi Christina Kampouraki, Dimitrios A. Giannakoudakis, Vaishakh Nair, Ahmad Hosseini-Bandegharaei, Juan Carlos Colmenares, Eleni A. Deliyanni. Metal Organic Frameworks as Desulfurization Adsorbents of DBT and 4,6-DMDBT from Fuels. Molecules. 2019; 24 (24):4525.
Chicago/Turabian StyleZoi Christina Kampouraki; Dimitrios A. Giannakoudakis; Vaishakh Nair; Ahmad Hosseini-Bandegharaei; Juan Carlos Colmenares; Eleni A. Deliyanni. 2019. "Metal Organic Frameworks as Desulfurization Adsorbents of DBT and 4,6-DMDBT from Fuels." Molecules 24, no. 24: 4525.
Commercial micro/mesoporous activated carbons were utilized as metal-free catalysts for the desulfurization of a model fuel, i.e. 4,6-dimethyldibenzothiophene (4,6-DMDBT) in hexadecane, under ambient conditions. Oxidation of carbons led to a further catalytic improvement.
Zoi Christina Kampouraki; Dimitrios A. Giannakoudakis; Konstantinos S. Triantafyllidis; Eleni A. Deliyanni. Catalytic oxidative desulfurization of a 4,6-DMDBT containing model fuel by metal-free activated carbons: the key role of surface chemistry. Green Chemistry 2019, 21, 6685 -6698.
AMA StyleZoi Christina Kampouraki, Dimitrios A. Giannakoudakis, Konstantinos S. Triantafyllidis, Eleni A. Deliyanni. Catalytic oxidative desulfurization of a 4,6-DMDBT containing model fuel by metal-free activated carbons: the key role of surface chemistry. Green Chemistry. 2019; 21 (24):6685-6698.
Chicago/Turabian StyleZoi Christina Kampouraki; Dimitrios A. Giannakoudakis; Konstantinos S. Triantafyllidis; Eleni A. Deliyanni. 2019. "Catalytic oxidative desulfurization of a 4,6-DMDBT containing model fuel by metal-free activated carbons: the key role of surface chemistry." Green Chemistry 21, no. 24: 6685-6698.
Background: Silk fibroin is the main protein of silk, and it has recently been evaluated for drug delivery applications due to its excellent properties. Specifically, silk fibroin exhibits good biocompatibility, biodegradability and low immunogenicity. Fibroin nanoparticles have attracted attention due to their high binding ability to different drugs as well as their ability for controlled drug release. The improvement of the therapeutic efficiency of drug encapsulation is important and depends on the particle size, the chemical structure and the properties of the silk fibroin nanoparticles. Methods: There is a variety of methods for the preparation of fibroin nanoparticles such as (i) electrospraying and desolvation method, (ii) supercritical fluid technologies, (iii) capillary-microdot technique, (iv) salting out etc. Furthermore, various techniques have been used for the characterization of nanoparticles such as SEM (scanning electron microscopy), TEM (transmission electron microscopy), DLS (dynamic light scattering), Zeta-potential and FTIR (Fourier transform infrared spectroscopy). Different drugs (paclitaxel, curcumin, 5-fluorouracil etc) have been encapsulated in fibroin nanoparticles. Results: Each separated synthesis method has different advantages such as (i) high yield, (ii) avoid use of toxic solvents, (iii) low cost, (iv) controllable particle size, (v) no organic solvent residue, (vi) simplicity of operation, (vii) small particles size, (viii) homeliness of operation, (ix) restrainable particle size, (x) easy and safe to operate, (xi) no use of organic solvent. Moreover, some major drugs studied are Floxuridine, Fluorouracil, Curcumin, Doxorubicin, Metotrexate, Paclitaxel and Doxorubicin, Horseradish peroxidase. All the above combinations (preparation method-drug) are studied in detail. Conclusion: Various drugs have been encapsulated successfully in silk fibroin and all of them exhibit a significant release rate. Finally, the encapsulation efficiency and release rate depend on the molecular weight of the drugs and it can be adjusted by controlling the crystallinity and concentration of silk fibroin.
Olga Gianak; George Z. Kyzas; Victoria F. Samanidou; Eleni A. Deliyanni. A Review for the Synthesis of Silk Fibroin Nanoparticles with Different Techniques and Their Ability to be Used for Drug Delivery. Current Analytical Chemistry 2019, 15, 339 -348.
AMA StyleOlga Gianak, George Z. Kyzas, Victoria F. Samanidou, Eleni A. Deliyanni. A Review for the Synthesis of Silk Fibroin Nanoparticles with Different Techniques and Their Ability to be Used for Drug Delivery. Current Analytical Chemistry. 2019; 15 (4):339-348.
Chicago/Turabian StyleOlga Gianak; George Z. Kyzas; Victoria F. Samanidou; Eleni A. Deliyanni. 2019. "A Review for the Synthesis of Silk Fibroin Nanoparticles with Different Techniques and Their Ability to be Used for Drug Delivery." Current Analytical Chemistry 15, no. 4: 339-348.
Magnetic graphene oxide was impregnated with polymers for the preparation of nanocomposite adsorbents to be examined for the adsorptive removal of a typical endocrine disruptor, bisphenol–A (BPA) from aqueous solutions. The polymers used were polystyrene, chitosan and polyaniline. The nanocomposites prepared were characterized for their structure, morphology and surface chemistry. The nanocomposites presented an increase adsorptive activity for BPA at ambient conditions, compared to pure magnetic oxide, attributed to the synergistic effect of the polymers and the magnetic graphene oxide. The increased adsorption of BPA exhibited by the nanocomposites with chitosan and polyaniline could be attributed to the contribution of amine groups.
Kyriazis Rekos; Zoi-Christina Kampouraki; Charalampos Sarafidis; Victoria Samanidou; Eleni Deliyanni. Graphene Oxide Based Magnetic Nanocomposites with Polymers as Effective Bisphenol–A Nanoadsorbents. Materials 2019, 12, 1987 .
AMA StyleKyriazis Rekos, Zoi-Christina Kampouraki, Charalampos Sarafidis, Victoria Samanidou, Eleni Deliyanni. Graphene Oxide Based Magnetic Nanocomposites with Polymers as Effective Bisphenol–A Nanoadsorbents. Materials. 2019; 12 (12):1987.
Chicago/Turabian StyleKyriazis Rekos; Zoi-Christina Kampouraki; Charalampos Sarafidis; Victoria Samanidou; Eleni Deliyanni. 2019. "Graphene Oxide Based Magnetic Nanocomposites with Polymers as Effective Bisphenol–A Nanoadsorbents." Materials 12, no. 12: 1987.
In the present study, a novel, simple, and fast sample preparation technique is described for the determination of four sulfonamides (SAs), namely Sulfathiazole (STZ), sulfamethizole (SMT), sulfadiazine (SDZ), and sulfanilamide (SN) in cow milk prior to HPLC. This method takes advantage of a novel material that combines the extractive properties of graphene oxide (GO) and the known properties of common polyurethane sponge (PU) and that makes sample preparation easy, fast, cheap and efficient. The PU-GO sponge was prepared by an easy and fast procedure and was characterized with FTIR spectroscopy. After the preparation of the sorbent material, a specific extraction protocol was optimized and combined with HPLC-UV determination could be applied for the sensitive analysis of trace SAs in milk. The proposed method showed good linearity while the coefficients of determination (R2) were found to be high (0.991-0.998). Accuracy observed was within the range 90.2-112.1% and precision was less than 12.5%. Limit of quantification for all analytes in milk was 50 μg kg-1. Furthermore, the PU-GO sponge as sorbent material offered a very clean extract, since no matrix effect was observed.
Martha Maggira; Eleni A. Deliyanni; Victoria F. Samanidou. Synthesis of Graphene Oxide Based Sponges and Their Study as Sorbents for Sample Preparation of Cow Milk Prior to HPLC Determination of Sulfonamides. Molecules 2019, 24, 2086 .
AMA StyleMartha Maggira, Eleni A. Deliyanni, Victoria F. Samanidou. Synthesis of Graphene Oxide Based Sponges and Their Study as Sorbents for Sample Preparation of Cow Milk Prior to HPLC Determination of Sulfonamides. Molecules. 2019; 24 (11):2086.
Chicago/Turabian StyleMartha Maggira; Eleni A. Deliyanni; Victoria F. Samanidou. 2019. "Synthesis of Graphene Oxide Based Sponges and Their Study as Sorbents for Sample Preparation of Cow Milk Prior to HPLC Determination of Sulfonamides." Molecules 24, no. 11: 2086.
The valorization of natural and renewable resources, like lignocellulosic biomass, towards value-added chemicals by low energy and economically viable processes still remains a global research and technological challenge. 5-hydroxymethylfurfural (HMF) is an important platform chemical that can be easily derived from biomass, and it can be further used as a feedstock for the production of building blocks for polymers or fuels. In this context, the partial oxidation of the hydroxyl group on the HMF molecule leads to the formation of the corresponding aldehyde, 2,5-diformylfuran (DFF), which may find multiple applications in bio-chemical industries. Herein, we present the synthesis and characterization of novel manganese (IV) oxide nanorods as catalyst for the HMF to DFF partial oxidation at ambient conditions. This 1D nanocatalyst operates at low energy light irradiation and without the addition of chemicals (bases or oxidants) as a highly selective photo-assisted catalyst. Under optimized experimental conditions, the HMF conversion was found to be above 99 %, while the DFF selectivity was almost 100 %. The presence of molecular O2 played a key role in triggering the selective oxidation, while the use of an aprotic and less polar organic solvent, such as acetonitrile, compared to water, further enhanced the reactivity of the catalyst.
Dimitrios A. Giannakoudakis; Vaishakh Nair; Ayesha Khan; Eleni A. Deliyanni; Juan Carlos Colmenares; Konstantinos S. Triantafyllidis. Additive-free photo-assisted selective partial oxidation at ambient conditions of 5-hydroxymethylfurfural by manganese (IV) oxide nanorods. Applied Catalysis B: Environmental 2019, 256, 117803 .
AMA StyleDimitrios A. Giannakoudakis, Vaishakh Nair, Ayesha Khan, Eleni A. Deliyanni, Juan Carlos Colmenares, Konstantinos S. Triantafyllidis. Additive-free photo-assisted selective partial oxidation at ambient conditions of 5-hydroxymethylfurfural by manganese (IV) oxide nanorods. Applied Catalysis B: Environmental. 2019; 256 ():117803.
Chicago/Turabian StyleDimitrios A. Giannakoudakis; Vaishakh Nair; Ayesha Khan; Eleni A. Deliyanni; Juan Carlos Colmenares; Konstantinos S. Triantafyllidis. 2019. "Additive-free photo-assisted selective partial oxidation at ambient conditions of 5-hydroxymethylfurfural by manganese (IV) oxide nanorods." Applied Catalysis B: Environmental 256, no. : 117803.
Sodium hydroxide-modified graphene oxide was used as manganese oxides support for the preparation of nanocomposites via a one-pot preparation route for the degradation of Reactive Black 5. The nanocomposites were characterized for their structure by X-ray diffraction, for their textural properties by Nitrogen adsorption, and for their surface chemistry by Fourier transform infrared spectroscopy, potentiometric titration, and thermal analysis measurements. The nanocomposites prepared showed to possess high activity for the degradation/oxidation of Reactive Black 5 at ambient conditions, without light irradiation, which was higher than that of the precursors manganese oxides and can be attributed to the synergistic effect of the manganese oxides and the modified graphene oxide.
Hayarpi Saroyan; Dimitra Ntagiou; Kyriazis Rekos; Eleni Deliyanni. Reactive Black 5 Degradation on Manganese Oxides Supported on Sodium Hydroxide Modified Graphene Oxide. Applied Sciences 2019, 9, 2167 .
AMA StyleHayarpi Saroyan, Dimitra Ntagiou, Kyriazis Rekos, Eleni Deliyanni. Reactive Black 5 Degradation on Manganese Oxides Supported on Sodium Hydroxide Modified Graphene Oxide. Applied Sciences. 2019; 9 (10):2167.
Chicago/Turabian StyleHayarpi Saroyan; Dimitra Ntagiou; Kyriazis Rekos; Eleni Deliyanni. 2019. "Reactive Black 5 Degradation on Manganese Oxides Supported on Sodium Hydroxide Modified Graphene Oxide." Applied Sciences 9, no. 10: 2167.
Sodium hydroxide modified graphene oxide was used as manganese oxide support for the preparation of three nanocomposite catalysts via a one-pot preparation route, for the degradation of an endocrine disruptor, bisphenol-A. The nanocomposites were characterized for their structure by X-ray diffraction, for their morphology with scanning electron microscopy and for their surface chemistry with Fourier transform infrared spectroscopy, potentiometric titration and thermal analysis measurements. The nanocomposites prepared showed to possess high catalytic activity for the degradation/oxidation of bisphenol-A at ambient conditions, without light irradiation and/or the addition of oxidants, which was higher than that of the pure manganese oxides and can be attributed to the synergistic effect of the manganese oxide and the modified graphene oxide. The increase degradation of bisphenol-A presented by the nanocomposite with the higher manganese percentage could be attributed to the different manganese oxide phase formed.
Hayarpi Saroyan; Dimitra Ntagiou; Victoria Samanidou; Eleni Deliyanni. Modified graphene oxide as manganese oxide support for bisphenol A degradation. Chemosphere 2019, 225, 524 -534.
AMA StyleHayarpi Saroyan, Dimitra Ntagiou, Victoria Samanidou, Eleni Deliyanni. Modified graphene oxide as manganese oxide support for bisphenol A degradation. Chemosphere. 2019; 225 ():524-534.
Chicago/Turabian StyleHayarpi Saroyan; Dimitra Ntagiou; Victoria Samanidou; Eleni Deliyanni. 2019. "Modified graphene oxide as manganese oxide support for bisphenol A degradation." Chemosphere 225, no. : 524-534.
In the present work, a commercial activated carbon was impregnated with MnO2 through a facile and efficient one-pot synthesis method. The impregnated carbon was characterized for the Mn content, the textural characteristics, the surface chemistry and the efficiency for removal and degradation of RB5. The MnO2 nanoparticles with an average size of 35 nm, were homogeneously dispersed in the carbon matrix and the BET surface area of the impregnated carbon found 760.77 m3 g−1. The efficiency for removal of RB5 was studied by batch tests under different experimental conditions. The treatment with H2O2 showed efficient removal and superior catalytic performance toward reactive black 5 (RB5) degradation that could be attributed to combined adsorption-degradation processes. The impregnated carbon proved to be an efficient catalyst for the oxidation- degradation of RB5 and presented good stability.
Hayarpi S. Saroyan; Anastasia Arampatzidou; Dimitra Voutsa; Nikolaos K. Lazaridis; Eleni A. Deliyanni. Activated carbon supported MnO2 for catalytic degradation of reactive black 5. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2019, 566, 166 -175.
AMA StyleHayarpi S. Saroyan, Anastasia Arampatzidou, Dimitra Voutsa, Nikolaos K. Lazaridis, Eleni A. Deliyanni. Activated carbon supported MnO2 for catalytic degradation of reactive black 5. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2019; 566 ():166-175.
Chicago/Turabian StyleHayarpi S. Saroyan; Anastasia Arampatzidou; Dimitra Voutsa; Nikolaos K. Lazaridis; Eleni A. Deliyanni. 2019. "Activated carbon supported MnO2 for catalytic degradation of reactive black 5." Colloids and Surfaces A: Physicochemical and Engineering Aspects 566, no. : 166-175.
Graphene oxide (GO) was used as a support for manganese oxide (MnO2) for the preparation of a nanocomposite catalyst for the degradation of an azo dye, Reactive Black 5 (RB5). The nanocomposite was characterized for the structure by XRD, for the morphology with SEM, and for the surface chemistry with FTIR and potentiometric titration measurements. The GO-MnO2 nanocomposite presented a high catalytic activity for the degradation/oxidation of RB5 at ambient conditions, which was higher than that of the pure MnO2 and could be attributed to the beneficial contribution of the manganese oxide and the graphene oxide.
Hayarpi Saroyan; George Z. Kyzas; Eleni A. Deliyanni. Effective Dye Degradation by Graphene Oxide Supported Manganese Oxide. Processes 2019, 7, 40 .
AMA StyleHayarpi Saroyan, George Z. Kyzas, Eleni A. Deliyanni. Effective Dye Degradation by Graphene Oxide Supported Manganese Oxide. Processes. 2019; 7 (1):40.
Chicago/Turabian StyleHayarpi Saroyan; George Z. Kyzas; Eleni A. Deliyanni. 2019. "Effective Dye Degradation by Graphene Oxide Supported Manganese Oxide." Processes 7, no. 1: 40.