Nonka Nedjalkova Daskalova

Nonka Nedjalkova Daskalova
Bulgarian Academy of Sciences | BAS · Institute of General and Inorganic Chemistry

Prof. DrSc

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59
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603
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Publications

Publications (59)
Article
Full-text available
The possibilities of 40.68 MHz radial-viewing inductively coupled plasma optical emission spectrometry equipped with a high-resolution spectrometer (spectral bandwidth = 5 pm) (HR-ICP-OES) were studied in the determination of rhenium in molybdenum and copper concentrates. By using equipment with a high spectral resolution, a hyperfine structure (HF...
Article
Full-text available
Optimization of the plasma operating conditions was carried out in aspect to achieve the lowest possible detection limits by using radial viewing 40.68 MHz inductively coupled plasma optical emission spectrometry (ICP-OES). Mg II 280.270 nm / Mg I 285.213 nm line intensity ratios (Mg II / Mg I) was measured to evaluate the robustness of the plasma...
Article
This paper deals with spectral interferences of complex matrix containing Mo, Al, Ti, Fe, Mg, Ca and Cu in the determination of rheniuminmolybdenumand copper concentrates by inductively coupled plasma optical emission spectrometry (ICP-OES). By radial viewing 40.68 MHz ICP equipped with a high resolution spectrometer (spectral bandwidth=5 pm) the h...
Article
Full-text available
Abstract. The economic importance of rare earth elements and platinum group of elements has led to the development of analytical methods, which have to ensure their accurate quantification in different type of samples. Radial viewing 40.68 MHz inductively coupled plasma optical emission spectrometry (ICP-OES) and the Q - concept for the quantificat...
Article
Full-text available
The economic importance of rare earth elements and platinum group of elements has led to the development of analytical methods, which have to ensure their accurate quantification in different type of samples. Radial viewing 40.68 MHz inductively coupled plasma optical emission spectrometry (ICP-OES) and the Q-concept for the quantification of spect...
Conference Paper
Full-text available
The economic and geological importance of Zr, Nb, Hf, Ta, Th, Pt, Pd, Rh and rare earth elements has led to the development of analytical methods, which have to ensure their accurate quantification in different type of samples. Radial viewing 40.68 MHz inductively coupled plasma optical emission spectrometry (ICP-OES) and Q - concept for the quanti...
Article
Full-text available
The possibilities and limitations of high resolution radial viewing 40.68 MHz inductively coupled plasma optical emission spectrometry (ICP - OES) were shown in the determination of As, Zn, Pt, B, Hg, Cd, Tl and U in environmental materials. Improvement of the detection limits was achieved by optimization of the operating conditions. The lowest det...
Article
Full-text available
This paper presents new quantitative data for the spectral interferences obtained by high resolution 40.68MHz radial viewing inductively coupled plasma optical emission spectrometry (HR-ICP-OES) in the determination of Zn, Cd, Sb, Cu, Mn, Pb, Sn, Cr, U, and Ba in environmental materials in the presence of a complex matrix, containing Al, Ca, Fe, Mg...
Conference Paper
Full-text available
Platinum groups of elements (PGEs) were doped in automobile catalytic converters. Since the introduction of catalytic converters, there has been a clear link between their use and the increasing emissions of these elements in the environment. By using a radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry and selected an...
Article
Full-text available
The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of...
Article
Full-text available
Samples of rime/fog water and dust in the air were collected in order to compare concentrations of pollutants. Particular attention was paid to particles of heavy metals (Al, As, Cu, Fe, Pb, Ti and Zn). The concentrations of pollutants from the air are different in rime water and fog water. Both (fog) water and ice crystals fixed Ti, Cu, As and Pb...
Article
Full-text available
This work shows that by using ICP-AES and the Q-concept for quantification of spectral interferences in the determination of Pt, Pd, Rh, Pb and Ba in catalytic automotive converters with aluminum as matrix component, the errors in the measurement of net line signals resulting from erroneous background determination can be eliminated. The auto-catal...
Article
Full-text available
This article is the seventh part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in ICP-AES. Radial viewing 27.12 MHz inductively coupled plasma atomic emission spectrometry (ICP-AES) was used in the determination of scandium, yttrium and rare earth elements in Tb2O3, Dy2O3, Ho2O3 and Tm2O3 as “pure” rare e...
Article
Full-text available
This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains data files and text files. The present article is the fourth part of a se...
Article
Full-text available
The concentration levels of heavy and toxic elements circulating in the environment increase due to various industrial activities. Now it is well understood that the environmental particles influence directly the cloud properties and atmosphere visibility, and indirectly change the global climate. Particles with aerodynamic diameter larger than app...
Article
Full-text available
A radial viewing 40.68 MHz ICP equipped with a 1 m Czerny-Turner monochromator (practical bandwidth 5 pm in the 2-nd order from 160 to 320 nm) was used for the determination of As, Mn, Cu, Pb, Zn, Cr and Ba in soils and sediments. The quantification of spectral interferences in the presence of Al, Ca, Mg, Fe and Ti as matrix constituents was made b...
Article
Full-text available
Radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometer was used in the determination of Y, Sc and rare earth elements in Eu2O3 or Lu2O3 as pure rare earth matrices. The Mg II 280.270 nm/Mg I 285.213 nm line intensity ratio was measured to evaluate the robustness of the operating conditions. The operating conditions were af...
Article
Full-text available
This paper deals with spectral interferences in radial - viewing Inductively Coupled Plasma Atomic Emission Spectrometry (lCP-AES) in the determination of Y, Zr, Nb, Hf, Ta and Th in geological materials.The spectral interferences in the presence of Al, Ca, Mg, Fe, Ti, Mn, Na, K and P as maffix constituents around the prominent lines of analytes we...
Article
Full-text available
This paper deals with spectral interference in radial—viewing Inductively Coupled Plasma Atomic Emission Spectrometry in the determination of As, Hg, Se, Tl, Sn and Bi in environmental materials. The spectral interferences, in the presence of Al, Ca, Mg, Fe and Ti as matrix constituents, around the prominent lines of analytes with wavelengths below...
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...
Conference Paper
Full-text available
The aim of this environmental study is to establish the distribution and the interaction of heavy metal water and soil pollution in Plovdiv - Assenovgrad region due to mining and metallurgical activities. The main pollution source is the smelter factory “KCM”, situated south of the town of Plovdiv. The dynamics and the evolution of concentration le...
Article
Full-text available
The present article discusses the spectral interferences affecting the determination of Ga, Ho and Tm as dopants in single crystals of potassium titanylphosphate (KTiOPO4) by inductively coupled plasma atomic emission spectrometry (ICP-AES). The Q concept, as proposed by Boumans and Vrakking [Spectrochim. Acta Part B 43 (1988) 69] was used for this...
Article
Full-text available
The present paper shows that inductively coupled plasma atomic emission spectrometry (ICP-AES) and the Q concept, in accordance with Boumans and Vrakking [Spectrochim. Acta Part B 43 (1988) 69] can be used in the determination of a large number of dopants with different characteristics (charge and ionic radius) in the single crystals of potassium t...
Conference Paper
Full-text available
The possibilities of different ICP-systems with radial viewing and different types of nebulizers in the determination of traces of toxic elements As, Hg, Se, Cd, Sb, Pb and Tl in biological materials were studied. The analysis of these materials is important in medical and forensic science applications. By using equipment including 40.68 MHz ICP, s...
Article
Full-text available
The present paper has shown that the Q concept, as proposed by P.W.J.M. Boumans, J.J.A.M. Vrakking, Spectrochim. Acta Part B 43 (1988) 69, can be used as a basic methodology in the determination of Ba, Cr, Cd, Mn, Pb and Zn in pairs of atmospheric particles by inductively coupled plasma atomic emission spectrometry (ICP-AES). The data base of Q val...
Article
Full-text available
The present article is the fifth part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES) The spectral interferences in the presence of gadolinium or erbium as interferents for 200-pm wide windows centered (±100 pm) around the prominent lines...
Article
This paper deals with spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES) encountered with environmental materials. These samples normally contain high concentrations of aluminium, calcium, magnesium, iron, titanium, potassium and sodium. The investigations cover: (a) spectral data for Al, Ca, Mg, Fe, Ti, K a...
Article
Full-text available
The content of the major constituents lithium, barium and phosphorus, and of the dopant in single crystals of copper-doped lithium-barium phosphates has been determined by inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry (spectrophotometry for phosphorus). The lack of statistical differences between t...
Article
The content of the major constituents lithium, barium and phosphorus, and of the dopant in single crystals of copper-doped lithium-barium phosphates has been determined by inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry (spectrophotometry for phosphorus). The lack of statistical differences between t...
Article
Full-text available
The present paper is a new application of inductively coupled plasma atomic emission spectrometry (ICP-AES) to the determination of Na, Cr, Mn, Fe, Co, Ni, Al, Mg, Rh, W, Pt, Ge, Rb, Zr, Nb, Ce, Nd, Eu, Tb, Er and Yb, present as dopants or impurities in single crystals of potassium titanylphosphate (KTP). The investigations cover: (a) spectral data...
Article
ICP-AES was applied to the determination of trace amounts of toxic elements in animal tissues, and also a large number of trace elements in bullet lead and silver. The analysis of these materials is important in forensic science applications.
Article
Full-text available
Inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry were applied to the determination of dopants (Ce, Nd, Eu and Er) and impurities (Fe, Na, Mg and Al) in the optical crystals of β-barium borate dissolved in hydrochloric acid. The matrix interferences occurring in analyses carried out by means of ICP-AES...
Article
Full-text available
Abstract This paper is the third part of a series of papers dealing with spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The present article shows: (a) the spectral data of europium interferent for 200 pm wide windows centred (±100 pm) about prominent lines of scandium, ytt...
Article
This paper is the second part of a series of papers dealing with mutual spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The present article covers: (a) the spectral data of praseodymium and samarium interferents for 200 pm wide windows centred (± 100 pm) about prominent line...
Article
The present paper deals with spectral interferences from cerium, neodymium and lanthanum on prominent lines of scandium, yttrium and rare earth elements (REE). The “true detection limit” criterion was used for rational wavelength line selection as proposed by boumans and vrakking [Spectrochim. Acta42B, 819 (1987); 43B, 69 (1988)]. Analysis lines se...
Article
The effect of different atmospheres-air, nitrogen, argon and helium-on the analytical properties of the “graphite arc” method used to analyse solutions were investigated. It was shown that the use of an argon atmosphere enables an analyst to achieve detection limits for elements with ionization potentials greater than 8.5 eV thirty to one hundred t...
Article
A brief survey of the known spectrographic methods for the determination of rhenium is presented. Results of the direct spectrographic method, “graphite arc” method and ICP-method for the determination of rhenium are summarized. The new methods permit it to realize limits of detection down to 2 × 10−8.
Article
Full-text available
The application of atomic emission spectrometric methods (AES) to the different stages of preparation of white sapphire and neodymium doped yttrium-aluminium garnet (Y3Al5O12 : Nd3+) single crystals is discussed. Optimum conditions for d.c. arc analysis of NH4Al(SO4)2·12H2O and Al2O3 were established and the detection limits for impurities were det...
Article
The influence of various potassium salts and barium nitrate on the axial distribution of ΔY = log Iline — log Ibackground was investigated in the case of the line In 303.9 nm. Comparative studies of the axial distribution were made for lines of the elements: Tl, Pb, Mg, Co, Cd, Zn, Hg in the presence of Ba(NO3)2 in air and in argon.The axial distri...
Article
analysis of dry residues from solutions is advantageous in determining elements having an ionization potential above 8.5 eV by their atomic lines. The increase in intensity of the latter is attained mainly due to an increase in the Boltzmann factor, i.e., due to an increased population of the corresponding levels because of the increase in the arc...
Article
To expand the range of elements determinable, we investigated the possibility of using a direct current arc, burning in a stream of argon. In [3-6], the results obtained in an investigation of the influence of the consumption of argon and an addition of the readily ionized element barium (in the form of its nitrate) on the parameters of the plasma...

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