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MAIN BRANCHES OF CHEMISTRY- Elemental Analysis- T.N.Shekhovtsova, V.I.Fadeeva
ELEMENTAL ANALYSIS
T.N. Shekhovtsova
Department of Chemistry, Lomonosov Moscow State University, Russia
V.I. Fadeeva
Department of Chemistry, Lomonosov Moscow State University, Russia
Keywords: chemical, physical methods; qualitative, quantitative elemental inorganic and
organic analysis; gravimetry, titrimetry; spectroscopic, electrochemical, kinetic, enzymatic,
chromatographic, test methods; fundamentals, practice.
Contents
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1 Introduction
1.1. Chemical Qualitative Inorganic Analysis
1.2. Chemical Qualitative Qrganic Analysis
2. Chemical qualitative elemental analysis
3. Physical methods of qualitative elemental analysis
3.1. Gravimetry
3.2. Titrimetry
3.3. Chemical Quantitative Elemental Organic Analysis
4. Chemical quantitative elemental analysis
4.1. Atomic Spectrometry
4.2. Molecular Absorption Spectrometry
4.3. Luminescence
4.4. Mass Spectrometry
4.5. Radiochemical Methods
4.6. Electrochemical Methods
4.7. Physical Methods of Local Surface Analysis
4.8. Distance Elemental Analysis
4.9. Kinetic Methods
4.10. Enzymatic Methods
4.11. Chromatographic Methods
4.12. Flow Injection Analysis
5. Physical methods of quantitative elemental analysis
6. Test methods
7. Applications of elemental analysis
Bibliography
Biographical Sketches
Summary
This article is devoted to one of the most actual problems of analytical chemistry –
elemental analysis that is the qualitative detection and quantitative determination of
chemical elements in the analyzed samples.
It describes the development and
improvement of methods of qualitative and quantitative elemental analysis during many
centuries, beginning at the first stage with methods, mainly based on chemical reactions
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MAIN BRANCHES OF CHEMISTRY- Elemental Analysis- T.N.Shekhovtsova, V.I.Fadeeva
and different processes (precipitation, dissolution, etc.). Nowadays physical methods,
based on physical properties of elements and products of their reactions, play the main role
in elemental analysis.
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Fundamentals and application of various chemical and physical methods of elemental
analysis, which differ in nature, assignment, metrological characteristics, are discussed.
Among chemical methods of quantitative elemental analysis, gravimetry and titrimetry are
described. Spectroscopic, electrochemical, kinetic, enzymatic, chromatographic methods,
as well as methods based on radioactivity, of elemental analysis are discussed among
physical methods. Spectroscopic methods of qualitative and quantitative elemental
inorganic and organic analysis are represented by atomic emission, atomic absorption
spectrometry, spectrophotometry, luminescence, X-ray fluorescence, and many others.
Special attention is paid to the application of mass spectrometry and neutron activation
analysis. Numerous examples of using such electrochemical methods as ionometry,
coulometry, and voltammetry are given. It is emphasized, that among all physical methods
of elemental analysis, spectroscopic methods are at the first position (about 70 per cent of
all analysis are carried out with their help), and nuclear methods are at the second place
(about 15 per cent). Mass spectrometry with inductively coupled plasma has the greatest
advantages: the absolute detection limit of an element can achieve 10-12 g and it is possible
to determine 60-70 elements in a sample simultaneously. Application of chemical,
physical, biochemical and test methods of elemental analysis in environmental control,
criminalistics, cosmochemistry, arts, etc. is discussed.
1. Introduction
Elemental analysis is the qualitative detection and quantitative determination of chemical
elements (atoms, ions) in a sample. To detect an element, one should fix an appearance of
an analytical signal: the formation of precipitate or characteristic crystals, color change, an
isolation of gaseous products, an appearance of a definite lines in spectrum, luminescence,
etc. To determine elements quantity, it is necessary to measure a value of an analytical
signal: a precipitate mass, intensity of a current, solution absorption, spectrum line,
luminescence or radioactivity, a reaction rate and so on. The content of an element is
calculated on the base of a functional dependence of the analytical signal value (AS) on a
mass or concentration of this element (AS = f (C)), which is established by calculations or
experiments. To obtain the analytical signal, chemical reactions of different types (acidbase, oxidation-reduction, complex formation), various processes (e.g., precipitation) as
well as different chemical, physical, biological properties of elements themselves or
products of their reactions, are used.
Methods for the detection and determination of elements are divided to chemical, physical
and biological. The most important characteristics of those methods are the detection limit,
sensitivity, selectivity, precision, rapidity and price of analysis.
2. Chemical Qualitative Elemental Analysis
Chemical elemental qualitative analysis arose from time immemorial. So, ancient Roman
historian Plyniy has described an application of a papyrus impregnated with a tannic-galls
extract for distinguishing copper from iron: the papyrus became black in a solution of iron
sulfate. There are some evidences that at the beginning of the XVIII century Russian Tsar
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Peter the First has made himself not very complicated chemical analysis for distinguishing
sulfur and arsenic, containing ores. R. Boyle (the XVII century) was the first to use
hydrogen sulfide as a chemical reagent for lead and tin determination; T. Bergman has
shown an important role of hydrogen sulfide in chemical analysis using it for the
precipitation of many metals sulfides. At the close of the XVIII and at the beginning of the
XIX centuries the majority of reagents for elemental qualitative analysis was known
already. In 1829 G. Rose was the first to describe not only reactions for individual elements
detection, but the first scheme for the systematic analysis of elements mixtures in his
“Handbook on analytical chemistry”. Modern hydrogen sulfide scheme for qualitative
analysis has been firstly formulated by C.R. Fresinius. Later, in the XX century the other
schemes, such as acid-base, ammoniac-phosphate, were also proposed.
In chemical methods of detection, the appearance of an analytical signal in the result of a
chemical reaction, is fixed visually, as a rule. Modern elemental qualitative analysis have
available numerous selective reactions with low limits of elements detection. To lower
limits of detection, one can use different approaches, such as extraction, flotation, drop
reactions on filter paper, micro crystalline, catalytic, luminescent reactions, etc.
2.1. Chemical Qualitative Inorganic Analysis
The detection of individual elements in a mixture with other accompanying elements is a
rather difficult problem, because all of them can interact with the same reagents with a
similar outward effect. Using specific reagents and reactions, makes it possible to detect
some elements in mixtures with a fractional method. For instance, starch is a specific
reagent for iodine detection (a blue compound is formed), alkali is used for nitrogen
detection in ammonia salts. Using different ways to improve selectivity (varying pH values,
temperature, masking, changing oxidation degree, etc.) allows us to increase a number of
elements, which can be individually detected in mixtures. Application of organic reagents
makes easier the fractional detection of elements. A typical example of such reagents is
dimethylglyoxime, which can be a specific reagent for the determination of nickel, forming
red complex with it under definite conditions (pH, masking interferents).
In those cases when elements can not be detected fractionally, it is necessary to separate
them preliminarily. Majority of separation methods are based on selective distributing
elements of an analyzed sample between two unmixed phases. The detected elements
should be transferred completely to one of such phases. Precipitation, extraction, thin-layer
chromatography are often used for elements separation in qualitative analysis. The
systematic schemes for analysis of elements mixtures are based on these separation
methods. When the precipitation is used for elements separation, the systematic scheme for
analysis includes a successive isolation of a small number of elements, their groups, with
the help of group reagents with their following fractional detection, some times additional
separation of elements of the same group is necessary. Inorganic (HCl, H2SO4, H2S,
Na2HPO4, NaOH, NH3), and organic (8-hydroxyquinoline, dimethylglyoxime, cuppherone)
precipitators are used as group reagents. Chromatographic separation of elements (thin-layer
and paper chromatography) is based on transferring components of a mobile phase through
a stationary phase with a different rate. In paper and thin-layer chromatography, cellulose
fiber of a paper and thin layers of different sorbents (metal oxides, silica gels, cellulose) on
plates are used as bearers for stationary phases (water, for instance). Various solvents or
their mixtures, organic and inorganic acids, can play the role of a mobile phase.
Components of a mobile phase form separate zones (spots) on plates or paper strips
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(chromatograms), which position is characterized by Rf-coefficient, or a relative rate of
different components transfer through a stationary phase. Colored zones on a chromatogram
can appear immediately, or as a result of developing invisible zones by correspondent
reagents, forming colored compounds with elements to be detected.
2.2. Chemical Qualitative Qrganic Analysis
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Contrary to qualitative inorganic analysis, the detection of elements in organic analysis
serves as a preliminary identification of characteristic functional groups of organic
compounds, containing a definite element. For example, if preliminary studying has shown
sulfur absence, it is not necessary to carry out reactions for the detection of SH-, SO3H- or
S-C- groups containing compounds. The main way to detect metals and non-metals
(excluding hydrogen and oxygen) while analyzing organic substances, is a distraction of
analyte molecules to obtain an inorganic compound which can be identified with chemical
reactions. For instance, in order to detect carbon in non-volatile compound, the latter should
be heated with KJO3 at 300-4000C for KI formation.
The products of this reaction are dissolved then in acidified water, and KI is detected owing
to the reaction 5I- + JO3- + 6H+ = 3H2O + 3I2. Halogen containing organic compounds,
after their mixing with copper oxide and following heating, form copper halogenides,
carbon dioxide and water. Copper halogenide can be detected by a typical blue–green flame
color. While heating nitrogen, arsenic and phosphorus-containing organic compounds with
calcium oxide, ammonia, calcium tertiary arsenate and phosphate, respectively, are formed.
Ammonia can be detected with the help of an indicator paper. Calcium phosphate is
dissolved in nitric acid and then phosphate-ions are precipitated by ammonia molybdate
solution, forming yellow crystals of ammonia molybdenum phosphate. Arsenic(V) can be
detected using its reaction with potassium iodide, since the product of this reaction – iodine,
forms a blue complex with starch.
Metals in organic substances are detected in solutions, obtained after burning to ashes, and
following dissolution of analyzed compounds in acids; either treatment with a hot
concentrated nitric acid (Carious method) or heating with a concentrated sulfuric acid
(Kyeldahl method) can be also used for this purpose. Metals identification can be carried
out by common methods for inorganic qualitative analysis.
3. Physical Methods of Qualitative Elemental Analysis
At present, elements are mostly detected with the help of physical methods, which are based
on physical phenomena or processes, e.g., an interaction of elements with an energetic
current. Among such methods, the method of atomic emission spectroscopy (AES), based
on a thermal excitation of atoms of free elements and registration of the optic spectrum of
excited atoms emission, should be distinguished first of all. This method was developed by
K. Kirchgoff and R. Bunsen (the XIX century). Since 1861 till 1932, 25 elements of the
Periodic System ( Cs, Rb, Tl, In, Ga, He, Ar, Ne, Kr, Xe, Hf and 14 rare earth elements)
were opened with the help of AES method. In 1932, hydrogen isotope – deuterium was
opened. The main advantage of the AES method is the possibility to identify with its help a
great number of elements in samples, since it allows us to fix a lot of emission lines, which
position in the spectrum is individual for each element. The most intensive, so called “last”
lines, which are the last to disappear in the spectrum, when the element concentration
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decreases, are used for elements detection. To improve the reliability of elements
identification, it is necessary to detect several lines of the same element in the spectrum.
The main merit of another spectroscopic method – the method of laser-atomic–fluorescence
spectroscopy (LAFS), is its high selectivity, which is conditioned by an exceptional
simplicity of atomic fluorescent spectrum, and hence, by an absence of a superposition of
spectrum lines of different elements.
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Methods of X-ray emission spectroscopy (XES) and X-ray fluorescence (XRF) are also
used for qualitative elemental analysis. These methods permit multielemental qualitative
analysis of solid samples. X-ray fluorescent emission gives an analyst one of the most
powerful means for the detection of heavy metals almost in any matrix and complicated
substances (e.g., it is possible to detect 1 per cent of tantalum in a sample of niobium with
an error ±0.04 per cent). XRF method can’t be used at all for detecting elements lighter than
sodium and can be partially applied for the detection of elements, which are situated in the
Periodic System before calcium.
Method of X-ray photoelectron spectrometry (XPS) allows carrying out indestructible
qualitative elemental analysis of solid samples surface, and it is possible to detect any
element from lithium to uranium. The analytical essence of qualitative X-ray photoelectron
analysis consists of individual values of electron energy in an atom of each element.
Luminescence is also often used for qualitative elemental analysis. Phenomenon of
luminescence consists in an emission of atoms, ions, molecules and other more complicated
particles, after absorbing energy of the excitation, and this emission is surplus in
comparison with a thermal emission of a solid at definite temperature. Not so many metal
ions (U, Sm, Eu, Tb, Dy) have their own luminescence in compounds (e.g., minerals). The
most interesting practical problem is detection of uranium in rocks and waters, based on the
mentioned phenomenon. The luminescent detection of metals is usually based on their
reactions with organic reagents, which result in forming luminescent compounds. So,
numerous derivatives of oxyazo- and oxyazomethine compounds are widely used for the
detection of Al, Ga, Mg and other elements which form uncolored complexes.
Mass-spectrometric method is widely practiced for elemental analysis of solid organic
compounds and materials. This method is based on the ionization of atoms and molecules of
a compound, and following separation of formed ions in space and in time. The
identification of elements consists in decoding mass-spectrum and a comparison of a
location of lines of an element to be sought for, and lines of a known main component or
added inner standard. This method allows detection of about 50 elements – admixtures in
different solid samples, using special instrumentation.
Radiometric methods, based on measuring radioactivity of natural radionuclides are used
for qualitative analysis of geographical samples. Thus, using γ-emission, allows us to find
uranium and thorium deposit and to solve other geological problems.
4. Chemical Quantitative Elemental Analysis
There are a lot of various methods, modes and devices for chemical quantitative elemental
analysis. Gravimetry and titrimetry were primary methods for quantitative analysis; even
now their precision is often higher than that of instrumental methods. Only coulometry and
electrogravimetry are characterized with a comparable precision.
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MAIN BRANCHES OF CHEMISTRY- Elemental Analysis- T.N.Shekhovtsova, V.I.Fadeeva
4.1. Gravimetry
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In gravimetry, an analyte is precipitated in the form of an insoluble compound of defined
stoichiometry. After collection and drying, the product is weighed on an analytical balance
and from the mass and known stoichiometry, the original analyte is quantitatively
determined. Sometimes, an analyte is isolated in a form of a volatile compound. Gravimetry
is an absolute (standard-free) method. This method is extremely accurate, owing to the fact
that it is possible to weigh substances to great accuracy with analytical balances; it is
common practice to determine a weight to 5 digits. For the first time gravimetry was
described in details by C.R. Fresinius in his Hand-book (1846). During the last century, a
lot of gravimetric methods for the determination of different elements were proposed. The
main field of gravimetry application is a precise determination of large and middle amounts
of elements with an error not more than 0.1-0.2 per cent. Inorganic and organic reagents are
used as precipitators. Thermogravimetry is applied for the direct determination of elements
without their separation; for instance, the content of calcium and barium can be determined
without their separation, using a derivatogram of their oxalates.
4.2. Titrimetry
Titrimetric method of analysis was developed in the middle of the XVIII century. The
essence of this method is in a measuring a volume or mass of a reagent solution, which is
spent to interact completely with a component to be determined. The endpoint of a reaction
is detected as a change of a solution color or any other parameters. It is worth mentioning
that J.L. Gay-Lussac (1778-1850) has made a valuable contribution to titrimetry
development. Owing to his investigations, the rapid, handy, rather precise titrimetric method
became widely practiced in scientific and industrial laboratories. But a real revolution in the
theory, instruments, procedure of titrimetric analysis has been connected with C.F. Mohr
(1806-1879). He proposed the first procedure for the determination of oxygen, solved in
water: he introduced a large amount of iron (III) salt to an analyzed solution, then added
alkali solution, kept it for a while and then titrated an excess of iron (III) by potassium
permanganate. This procedure is used in practice till now.
There are a lot of various reactions used in titrimetry: acid-base, redox, complex formation.
In quantitative elemental analysis, methods based on redox and complex forming reactions
(complexometric titrations) are mostly used, although acid-base titrimetric method for
nitrogen determination still remains a classic one. According to that method, nitrogen in any
oxidation degree in an analyzed sample should be transferred primarily to ammonium-ion.
Organic compounds are decomposed accordingly to Kyeldahl method; inorganic nitrates
and nitrites are reduced by metals. After the decomposition, a sample is treated by alkali,
and ammonia is distilled off and absorbed by a standard solution of hydrochloric or boric
acids.
Among redox methods of titration, permanganatometry and dichromatometry should be
distinguished as the best methods for iron determination in different samples (ores,
minerals, alloys). Bromatometry is the best method for tin and stibium determination;
iodometry is the best and the most precise method for the determination of rather large
contents of copper in alloys, ores, high temperature superconductors.
Unique properties of polycarbonic acids – complexones - complexing agents with chelating
properties, forming stable water soluble chelate complexes with simple stoichiometry,
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conditioned a possibility of their application as titrants in complexometry. Almost all such
methods are based on using one complexone – ethylenediaminetetraacetic acid disodium
salt – EDTA. A valuable contribution to the development of this method was made by
Swiss scientist G.K. Schwarzenbach, as well as by Czech chemist R. Prishbill (30-50th years
of the XX century).
For better understanding the role of complexones in elemental analysis, suffice it to say, that
now more, than 60 elements can be determined by the direct or indirect method with the
help of complexones. There is no doubt, that the most important and early application of
EDTA in titrimetry was the determination of water hardness, that is the determination of a
total and individual content of calcium and magnesium in waters.
4.3. Chemical Quantitative Elemental Organic Analysis
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The aim of elemental organic analysis in general is the determination of the elemental
composition of organic compounds. Major constituents of organic substances are C, H, N, S
and O besides halogens, P and metals. A complete knowledge of the percentage of the
elements in a compound in addition to its molecular weight makes the calculation of the
molecular sum formula possible. Historically, methods of elemental analysis of organic
compounds, based on their oxidation and the following gravimetric, titrimetric or
gasometric determination of formed simple compounds of individual elements, have been
first developed. First analysis of such type was conducted by A.L. Lavoisier (at the end of
the XVIII century); for example, he found that the ratio C:H in alcohol was 3,6:1 (true ratio
is 4:1). The main classical scheme for the determination of carbon and hydrogen was
developed by German scientist J. Liebig at the first part of the XIX century. French scientist
J.B.A. Dumas carried out the procedure for nitrogen determination (1831), but nowadays
the Kyeldahl method (1883) is of particular importance. In 1834 E. Anri and W.C. Zeise
proposed to determine sulfur in organic compounds by their decomposition in the presence
of oxidants, with the following gravimetric determination of formed sulfate-ion. Such
approach is used even now, but the sequence of operations and range of oxidants have
changed.
Today chemical macroanalyses are rarely used for organic elemental analysis; they are
almost completely supplanted by more rapid, convenient and precise microanalysis. It is
necessary to emphasize, that microanalysis differs from macroanalysis not only by the scale,
instruments and technique of conducting operations that is another method of analysis in
principle. Now microanalysis plays an important role in physiology, biology, biochemistry.
The principle of elemental organic microanalysis was developed by Austrian scientist Fritz
Pregl (Nobel Prize 1923) and is still valid in today’s modern instrumental techniques of
elemental organic analysis. It consists of disintegration of a precisely weighed amount of a
sample by rapid combustion (oxidation) in an oxygen stream at high temperatures (10000C
to 18000 0C), of separation of the reaction products and of subsequent detection of the
minute amounts of the gases produced by the combustion as well as a final calculation step.
5. Physical Methods of Quantitative Elemental Analysis
Among numerous physical (instrumental) methods of elemental analysis, spectroscopic
methods are mostly used (≈ 67 per cent), besides, nuclear (≈ 14 per cent), electrochemical
(≈ 6 per cent) and all other (≈ 3 per cent) methods are applied. The comparison of the
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MAIN BRANCHES OF CHEMISTRY- Elemental Analysis- T.N.Shekhovtsova, V.I.Fadeeva
relative detection limits of different methods of elemental analysis, shows that values of the
detection limits enhance in the following row of the methods: laser atomic ionization and
atomic fluorescence; radioactivation, solid mass-spectrometry, kinetic methods. The
comparison of two parameters – the detection limit and a number of determined elements,
shows, that the combination of mass spectrometry and inductively coupled plasma, has the
main advantages. Methods of atomic spectrometry, mass spectrometry and methods, based
on radioactivity, are the most typical methods for quantitative elemental analysis.
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Bibliography
Analytical Chemistry. Ed. by Kellner R., Mermet J.-M., Otto M., Widmer H.M. (1998). 916 pp. Wiley-VCH
Verlag, GmbH, D-69469 Weinheim, FRG. [This describes fundamentals and applications of chemical and
physical: atomic emission, atomic absorption spectrometry, X-ray fluorescence, activation analysis, mass
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Analytical Chemistry. Ed. by Zolotov Yu.A. (2000). V.1. 351 pp. V.2. 493 pp. High School (in Russian).
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qualitative and quantitative elemental analysis].
Bard A.J., Faunkner L.R. (1980). Electrochemical Methods; Fundamentals and Applications. John Wiley &
Sons. New York, Chichester, Brisbane, Toronto. [This describes fundamentals of electrochemical methods
and includes examples of applications of those methods for quantitative elemental analysis].
Jungreis E. (1997). Spot Test Analysis. 377 pp. New York et al: John Wiley & Sons.[This gives the
information on the essence and applications of test methods].
Mazor L. (1986). Methods of Organic Analysis. 584 pp. Budapest. Akademiai Kiado. [This represents
methods of qualitative and quantitative elemental and functional analysis of organic compounds]
Mottola H.A. (1988). Kinetic Aspects of Analytical Chemistry. Chemical Analysis. V.96. 285 pp. John
Wiley & Sons. New York, Chichester, Brisbane, Toronto, Singapore. [This represents fundamentals and
applications of kinetic and enzymatic methods for elemental analysis].
Pohloudek-Fabini R., Beyrich Th. (1975). Organische Analyse, unter besonderer Berücksichtigung von
Arzneistoffen.600 pp. Leipzig. Akademishe Verlagsgesellschaft Geest & Portg K.-G. [This includes
numerous examples of detection and determination of elements and functional groups in organic
compounds].
Winefordner J.D. (1976). Trace Analysis. Spectroscopic methods for elements. New York, London, Sydney,
Toronto: John Wiley & Sons. [This work gives a lot of information on fundamentals and use of spectroscopic
methods in chemical analysis, and for elemental analysis, in particular].
Zolotov Yu.A., Kuz’min N.M. (1990). Preconcentration of Trace elements. Amsterdam et al. Elsevier. 372
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Biographical Sketches
Tatyana N. Shekhovtsova was born in 1947. In 1965 she graduated from the High School and entered the
Chemistry Department of Lomonosov Moscow State University (MSU); graduated from it in 1970. In the
same 1970 she was employed in Analytical Chemistry Division of Chemistry Department of Moscow State
University as a junior scientist. In 1974 she got Ph.D. in Analytical chemistry at the same Chemistry
Department of MSU. In 1975 she was promoted to an assistant professor, in 1987 - to an associate professor,
in 1996 - to a full professor of Analytical Chemistry Division of Chemistry Department of MSU. In 1996
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MAIN BRANCHES OF CHEMISTRY- Elemental Analysis- T.N.Shekhovtsova, V.I.Fadeeva
she obtained the scientific degree Doctor of science in Analytical chemistry. Tatyana N. Shekhovtsova is a
Deputy Head of Analytical Chemistry Division of Chemistry Department of MSU; a member of the
Scientific Council on Analytical Chemistry of Russian Academy of Sciences, the Head of its two
commissions: the commission on analytical chemistry education in universities and the commission on
biochemical methods of analysis.As a full professor of analytical Chemistry, she delivers lectures on the
basic course of analytical chemistry for undergraduate students of Chemistry Department of MSU, special
lecture course on kinetic and enzymatic methods for graduates. Her scientific interests are: development of
fundamentals and practice of enzymatic methods in chemical analysis; application of native and immobilized
enzymes of different classes and isolated from diverse sources, and apoenzymes for the determination of
biologically active inorganic and organic compounds – enzymes effectors (inhibitors and activators). She is
an author of more than 200 scientific publications in Russian and International Journals, co-author of three
text books for students on fundamentals and applications of different methods of analytical chemistry. She
gave oral and plenary presentations at numerous scientific Russian and International Conferences and
Symposiums.
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Valentina I. Fadeeva was born in 1929. In 1948 she entered the Chemistry Department of Lomonosov
Moscow State University (MSU) and graduated from it in 1953. In 1963 she got Ph.D. Now she is an
associated professor of Analytical Chemistry Division of Chemistry Department of MSU. She delivers
lectures for undergraduate and graduate students of Chemistry Department on various aspects of analytical
chemistry. She is a co-author of two text books for students on fundamentals and applications of different
methods of analytical chemistry. Her scientific interests are: development of fundamentals of complex
formation in heterogeneous systems, sorption and extraction concentration of metal ions complexes;
development of hybrid methods for analysis of industrial and environmental samples. She is an author of
more than 130 scientific publications in Russian and International Journals, participated in many scientific
Russian and International Conferences and Symposiums.
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