Albena K. Detcheva

Albena K. Detcheva
Bulgarian Academy of Sciences | BAS · Institute of General and Inorganic Chemistry

PhD

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60
Publications
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536
Citations
Citations since 2016
14 Research Items
204 Citations
20162017201820192020202120220102030
20162017201820192020202120220102030
20162017201820192020202120220102030
20162017201820192020202120220102030

Publications

Publications (60)
Article
Full-text available
The aim of the present study is the effective application of chemometric approach to the elemental composition of a data set of ten ethereal oil plant materials. The contents of 28 essential and toxic mineral elements at main, minor and trace level are determined in each sample by means of direct solid sampling electrothermal vapourization inductiv...
Article
The efficiency of a material based on the plant Thymus vulgaris L. for Cu(II) removal from aqueous solutions is investigated. The estimation of optimal parameters influencing the Cu(II) adsorption was studied by the batch method. Optimum pH value was found to be about 4. Kinetic of Cu(II) adsorption was very fast. Equilibrium experimental data were...
Article
A method, based on electrothermal vaporization (ETV) coupled to inductively coupled plasma optical emission spectrometry (ICP OES), has been optimized for direct solid sampling analysis of soda-lime glass—the most common...
Article
Full-text available
The objective of the present study is the characterization of an adsorbent plant material based on Hypericum perforatum L. and the investigation of its feasibility for the removal of Cu2+ ions from aqueous solutions. XRD, TGA, FTIR, SEM and low-temperature nitrogen adsorption were used for the analytical characterization of the material. Particle s...
Article
Full-text available
The content of essential, non-essential and toxic elements in seven commercially available and widely consumed for medicinal purposes Bulgarian herbs was determined by means of an optimized electrothermal vaporization induc-tively coupled plasma optical emission spectrometric (ETV-ICP-OES) method in one run. Plasma observation was axial and torch a...
Article
Full-text available
Two biomaterials based on the abundant Bulgarian medicinal plants Mentha spicata L. (denoted as MS) and Ruta graveolens L. (denoted as RG) were investigated as environmentally friendly biosorbents for Cu(II) removal from aqueous solutions. Grain size distribution, slurry pH, texture parameters, thermal behavior and mineralogical composition of MS a...
Article
In the present study an electrothermal vaporization inductively coupled plasma optical emission spectrometric (ETV-ICP-OES) method was used to establish the elemental composition of late-antique and early-Christian glass artefacts from South-West Bulgaria. The finely ground glass samples were analyzed directly and CF4 was used as evaporation and tr...
Article
A study on the colouration of late-antique and medieval glass finds excavated on the territory of present Bulgaria was performed. Optimized total reflection x-ray fluorescence (TXRF) procedure was used for determining the concentrations of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc in the glass fragments. The sam...
Article
Full-text available
The feasibility of using Mentha spicata L. (MS) and Ruta graveolens L. (RG) for the removal of Cd²⁺ions from aqueous solution was investigated. Batch experiments were performed to evaluate the effect of contact time, acidity and initial metal concentration on Cd²⁺removal from aqueous solutions. Equilibrium experimental data were fitted to linear La...
Article
Full-text available
In the present study raw coal bottom ashes from four Bulgarian coal-fired power plants – “Bobov dol”, “Maritsa Iztok-3”, “Republika” and “Sliven” were investigated by a combination of different analytical methods. They were characterized in terms of mineralogical and chemical composition, grain size distribution, conductivity, moisture, slurry pH,...
Article
Full-text available
In the present work, the adsorption of Ag+ ions on hydrolyzed plant biomass (willow, paulownia, wheat straw and maize stalks) was investigated. Chemical analyses were performed to establish the composition of the obtained materials. Adsorption mechanism, adsorption sites and specific surface areas of these materials were examined by BET analysis, I...
Article
Full-text available
In the present study agricultural waste (rice husks) was used for the production of biogenic silica. The resulting material was obtained by incineration of rice husks at a temperature of 800° С and was characterized by means of XRD, FTIR, SEM-EDS, Hg-porosimetry and N2-adsorption. The adsorption ability of the rice husks ash towards Fe(III), Pb(II)...
Article
Ten brands of Bulgarian bottled mineral, spring and table waters were subjected to chemometric expertise using cluster analysis and principal components analysis. The waters were classified into several patterns depending on their microelement composition. Groups of similarity between the chemical components of the potable waters were found and the...
Article
In supplementary work to the one published earlier, experiments with SF6, NF3, CF4 and H2 as new modifier gases for the matrix studied were performed. Our investigations were continued to improve the described analytical method and to achieve additional insights into the mechanism of analyte release. Our new survey is split in two parts. At first f...
Article
Full-text available
Pb in raw coal fly ash from five Bulgarian power plants were determined by total reflection X-ray fluorescence (TXRF), using gallium as the internal standard. The samples were analysed as in slurry form in Triton TM X-114. The experimental parameters, such as grain size, concentrations of fly ash slurry and excitation time were optimised. For valid...
Article
Full-text available
The present paper deals with chemical and physicochemical characterization of seven glass fragments of medieval glass bracelets from South-East Bulgaria. Samples were investigated by Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and differential thermal analysis (DTA). Gravimetric chemical analysis was used...
Article
The contents of 3d-transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) in fragments of medieval glass bracelets, found in the necropolis of Stam-bolovo and the castle of Mezek, Bulgaria, were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The samples were analysed as slurries in Triton X 1...
Article
The contents of 3d-transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) in fragments of medieval glass bracelets, found in the necropolis of Stam-bolovo and the castle of Mezek, Bulgaria, were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The samples were analysed as slurries in Triton X 1...
Article
Full-text available
The content of S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, As, Br, Rb and Ba in several brands of Bulgarian bottled potable waters (" Savina " table, " Gorna Banya " mineral, " Bankya " mineral, " Kom " mineral, " Thorn Spring " mineral, " Hissar " mineral, " Devin " spring and mineral and " Mihalkovo " spring and mineral) was determined by total reflection...
Article
The contents of 3d-transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) in fragments of medieval glass bracelets, found in the necropolis of Stam-bolovo and the castle of Mezek, Bulgaria, were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The samples were analysed as slurries in Triton X 1...
Article
Full-text available
In the present study the adsorption properties of coal fly ashes from Bul- garian power plants were investigated. Batch experiments were performed to evaluate the effect of contact time, acidity, initial metal concentration on Cu(II) removal from aqueous solutions. Equilibrium experimental data were fitted to linear Langmuir and Freundlich models....
Article
Full-text available
Raw coal fly ashes from five Bulgarian power plants were used in the present study. They were characterized in terms of mineralogical and chemical composition, grain size distribution, specific surface area and pore size, conductivity, moisture, slurry pH, ignition losses and adsorption properties by the combined use of analytical techniques. Equil...
Article
Full-text available
Four carbon/silica-containing materials obtained by pyrolysis of rice husks were characterized and their adsorption properties towards some metal ions were evaluated. GC/MS analysis and FT-IR spectroscopy were applied for identification of functional groups finely dispersed on the surface. Their amounts were gravimetrically determined after extract...
Article
Full-text available
In the present study four functionalized mesoporous silica materials denoted as BIS-1, BIS-2, BIS-3 and BIS-4 have been synthesized through a simple co-condensation of bis-[3-(trimethoxyosilyl)propyl] amine (BTPA) and tetraethyl orthosilicate (TEOS). The influence of the BTPA amount on the structural and adsorption properties of the resultant mater...
Article
Full-text available
The trace elements S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, As, Br, Rb and Ba in Bulgarian bottled mineral waters of low and high total dissolved solids (TDS) content were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The water samples were analysed after simple preparation consisting in three-fold s...
Article
The content of Fe, Zn, Cu, Pb and Cd is determined in tomato fruits. The role of fertilization on the content of these elements is also studied. The investigated fertilizers (K2SO4 and KNO3) facilitate the extraction of Cu and its accumulation. The contents of Zn and Fe in tomato fruits is not influenced by their amounts in the fertilizer, but only...
Article
Full-text available
The adsorption properties of two new nanostructured hybrid materials containing B2O3 and ZrO2 were studied. The new organic-inorganic materials were synthesized via a sol-gel method. As a modifying agent, a quantity of 10 wt.% Zr(OPr)4 or B(OCH3)3 was added. The structure of the hybrid materials was investigated by means of (Fourier transform infra...
Article
Full-text available
Natural Bulgarian diatomite modified by oxidation with sulfuric acid and H2O2 or by coating with manganese oxide was characterized considering its chemical composition, surface area, pore volume, and structure. Modified diatomites displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored their sorp...
Article
Full-text available
In the present study the possibilities of electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP-OES) for characterization of archaeological glasses were investigated. The objects of our research were fragments of a colorless late antique Roman flat window glass (fifth century A.D.) and colored medieval glass...
Article
The concept of green chemistry emerged in the 1990s with the aim of minimizing the environmental impact of chemical activities. The basic principles to which a chemical procedure should correspond in order to be recognized as environmentally friendly (green) are reviewed. These include reduction of reagent and solvent usage, minimization of solid,...
Article
Full-text available
In the present work the adsorption of some transition metal ions from aqueous solutions on a silica-based nanostructured hybrid material modified by aluminium was investigated. The novel organic-inorganic material was synthesized via a sol-gel method through hydrolysis and co-condensation reactions. Its structure was characterized by means of SEM,...
Article
Full-text available
The possibilities for removal of toxic ions from aqueous solutions by novel porous material obtained from Bulgarian lignite and its oxidized modifications were studied. Adsorption of Hg(II), Cd(II), Pb(II), As(III), and As(V) ions was investigated using aqueous solutions with different concentrations and acidity. Equilibrium modeling data were fitt...
Article
Full-text available
Natural fluorite is used for growing CaF2 boules from melt by an improved technique. Chemical treatment of the starting ore decomposes the accessory minerals, thus producing small amounts of the oxides of Si, Al, and Fe insoluble in the melt, whereas the overall content of rare earth elements (REEs) of hundreds of μg g−1, remains unchanged. Analyti...
Article
Full-text available
In the present work the adsorption of lead from aqueous solutions on a novel nanostructured di-urethanesil hybrid material modified by aluminium was investigated. The adsorption properties of this material with respect to Pb(II) ions from single-component aqueous solutions and multi-component aqueous solutions containing also Cu(II), Cr(III), Cd(II...
Article
Full-text available
The main purpose of the present work was to study the adsorption of some transition metal ions from aqueous solution via a novel porous material obtained from Bulgarian lignite (Chukurovo deposit) and its oxidized modifications. The adsorption of Cu(II), Fe(III), Cr(III) and Au(III) ions was investigated using batch methods to study solutions with...
Data
The main purpose of the present work was to study the adsorption of some transition metal ions from aqueous solution via a novel porous material obtained from Bulgarian lignite (Chukurovo deposit) and its oxidized modifications. The adsorption of Cu(II), Fe(III), Cr(III) and Au(III) ions was investigated using batch methods to study solutions with...
Article
This paper discusses the microstructure and stability of medieval glass bracelets from 11th–13th cent. AD excavated in Drastar Castle, Bulgaria. All considered fragments represent high-magnesia soda–lime–silica glasses. Their chemical composition is determined by classical wet chemical analysis. Samples are investigated by infrared spectroscopy, X-...
Article
Full-text available
In the present work fragments of a colourless Roman flat window glass and coloured medieval glass bracelets excavated in the regions of Pernik and Silistra (Bulgaria) are studied. Data on the coordination of some colouring elements in the glasses are obtained by molecular absorption spectrometry of solid samples. The content of typical colouring an...
Article
Full-text available
Since ancient times glass was used for manufacturing of glass jewelry. Object of our study were medieval glass bracelets from XI–XIII AD excavated in Drastar–castle (Silistra, Bulgaria). Weight chemical analysis was applied for sil-ica assessment. The other oxides were determined by flame photometry (sodium and potassium) or flame atomic absorption...
Article
Full-text available
Since ancient times glass was used for manufacturing of glass jewelry. Object of our study were medieval glass bracelets from XI–XIII AD excavated in Drastar–castle (Silistra, Bulgaria). Weight chemical analysis was applied for sil-ica assessment. The other oxides were determined by flame photometry (sodium and potassium) or flame atomic absorption...
Article
The possibilities for universal calibration based on multi-element aqueous standard solutions and graphite laboratory reference materials (graphite standards) for the electrothermal vaporization inductively coupled plasma optical emission spectrometric (ETV ICP OES) determination of Al, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, P, Pb, S, Sr, Ti, V, and Zn...
Article
Direct solid sampling Zeeman atomic absorption spectrometric methods were developed and successfully applied to the determination of mercury, cadmium, lead and manganese in aquatic plants. Mercury was determined using a specially designed furnace. The other elements were determined by a third generation spectrometer. In 3-field- and dynamic mode th...
Article
Certified reference materials (CRMs) of different origin were used to validate the direct determination of total mercury by solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS) and a specially designed furnace. The temperature program provides only for one step. Atomisation of mercury and pyrolysis of the matrix is performed at a constant...
Article
Direct solid sampling Zeeman atomic absorption spectrometric methods were developed and applied to the determination of mercury, cadmium, manganese, lead and tin in seafood. All elements but mercury were measured by a third generation Zeeman atomic absorption spectrometry combined with an automatic solid sampler. In 3-field- and dynamic mode the ca...
Article
Full-text available
A simple and rapid slurry sampling electrothermal atomic absorption spectrometric (ETAAS) method was developed for the determination of traces of sodium and iron in single crystals of rubidium titanyl phosphate (RTP). The finely ground crystal material was dispersed in 5?mL of 2% (v/v) HNO 3, containing 0.005% (v/v) Triton-X-100. The fast furnace E...
Article
Full-text available
Two methods of opening fluid inclusions in hydrothermal quartz from Madan (Bulgaria) – mechanical (crushing) and thermal (decrepitation), followed by water leaching of the released components – were applied and compared. Problems concerning the sample preparation procedure, such as choice of an optimal sample mass and grain fraction, contamination...
Conference Paper
Full-text available
The electrothermal atomization of thallium in different matrices from a refractory metal platform consisting of a tungsten coil on tantalum foil with the dimensions of a conventional graphite platform was studied. Two chemical modifiers - ammonium tungstate, added as a solution or iridium as a permanent modifier were used. Best performance as regar...
Article
The content of the major components Sr, Li, Ti, Fe and Nb in single crystals, based on strontium–lithium–titanium oxides has been determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The single crystals have been grown from high temperature solutions of the oxide systems SrO–TiO2–LiBO2 or SrO–TiO2–Fe2O3–Nb2O5–LiBO2. Hydr...
Article
Full-text available
Slurry sampling ETAAS was successfully applied to the determination of sodium impurities in single crystals of potassium titanyl phosphate (KTP) and potassium gadolinium tungstate (KGW). Platform atomizers coated with titanium carbide or tungsten carbide, respectively, were used in order to avoid sensitivity drift due to the changes in the composit...
Article
Full-text available
The electrothermal atomization of the volatile elements arsenic, antimony and thallium from a refractory metal platform consisting of a tungsten coil and/or a refractory metal foil with the dimensions of a conventional graphite platform was studied. Several combinations of refractory metal platforms were investigated, as follows: W platform; Ta pla...
Conference Paper
Full-text available
Slurry Sampling ETAAS is a rapid, simple and reliable technique for trace analysis in hardly soluble materials. This technique was applied to the determination of iron impurities in optical crystals of potassium titanyl phosphate (KTP) and potassium gadolinium tungstate (KGW). Calibration curves with aqueous standards could be used for the KTP slur...
Article
Full-text available
This paper gives a brief information of investigations with a modern ETV-ICP system concerning its optimisation and performance. Analytical lines for the determination of trace elements were investigated as well as some other parameters like tube material, nozzle design etc. The new improved system was run under the optimized conditions for the ana...
Article
Direct solid sampling graphite furnace AAS (SS-GF-AAS) provides an advantageous alternative to the conventional AAS which requires wet digestion of the samples. This method is suitable for trace element determination in calcium fluoride and other fluoride-containing samples. Matrix effects were studied by using calibration standards, certified refe...
Article
Several chemical modifiers based on palladium have been evaluated: the individual Pd(II) and the mixed modifiers Pd + Zr, Pd + W, Pd + Zr + citric acid, Pd + W + citric acid. The mechanisms by which these chemical modifiers stabilize analytes and control atomization have been suggested. Factors that might have an influence on the characteristic mas...
Article
A method is described for the determination of arsenic(III) and arsenic(V) in water samples. The sample (adjusted to pH 2.5 to 3.5 with HCl or NaOH) is passed through a chromatographic column filled with inert support modified with the organotin reagent (C8H17)2SnCl2. Under these conditions arsenate is quantitatively retained, while arsenite is not...
Article
ETV-ICP-OES combinations are well known as powerful and cost effective systems in research and development up to the industrial routine analysis especially when they are equipped with automatic sample changers. The field of application is far diversified and is extended from general inorganic raw materials beyond ceramic, geological and environment...

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