|
Лаборатория "Аналитична химия" |
|
Научен колектив: Ръководител на лабораторията: ст. н. с. I ст. дхн Елисавета Иванова e-mail: eliva@svr.igic.bas.bg - ст. н. с. II ст. д-р Огнян Божковe-mail: bozhkov@svr.igic.bas.bg - ст. н. с. II ст. д-р Албена Дечева e-mail: albena@svr.igic.bas.bg - н. с. I ст. д-р Галя Генчева e-mail: gentg@svr.igic.bas.bg
Химици: Александър Петров, Боряна Коцева, Владимир Димитров, Добромира Лекова, Методи Младенов, Ралица ВелиноваMain fields of research: Analytical chemistry of rare toxic and essential elements, spectrophotometry, atomic absorption spectrometry, X-ray fluorescence spectrometry, mass spectrometry, separation and concentration methods, chemical speciation, environmental analytical chemistry, chemical metrology. The Laboratory of Analytical Chemistry is divided into several research groups: Separation and Preconcentration Methods Научна група „Рентгенофлуоресцентен анализ” Spectrophotometrical methods of analysis Atomic absorption spectrometry
Research group “Separation and Preconcentration Methods”Research activities The research activities of the group are focused on the development of methods for sample preparation with a view to subsequent trace element determination by atomic spectrometry. Special emphasis is laid on the methods for trace element preconcentration and separation from the matrix. Various analytical approaches are used, e.g. solvent extraction, sorbent extraction, ion exchange a.o. in flow injection, column and batch performance. The methods developed are applied to the determination of the trace element content in industrial, environmental and clinical samples, as well as to the analytical characterization of novel optical crystal materials. Recent scientific projectsA) “Flow injection separation and preconcentration of metal complexes in a knotted reactor coupled on-line with ICP-TOFMS or ETAAS. Application for the determination of toxic trace elements in environmental samples and biological materials” with the Micro- and Trace Analysis Centre of the University of Antwerp, sponsored within the framework of scientific cooperation between the Bulgarian Academy of Sciences and the Flamish Fund for Scientific Research – Belgium. B) “Ternary tungstates and borates of alkali metals and aluminium: synthesis, structure, growth of pure and doped crystals, optical properties and application as advanced materials”, sponsored by the Fund for scientific research of the Bulgarian Ministry of Science and Education. C) “Determination of trace elements in Bulgarian mineral waters by X-ray fluorescence spectrometry after preliminary separation and preconcentration”, sponsored by the Bulgarian Academy of Sciences. Research group “Chemical speciation” Research activities Arsenic and selenium are present in ground waters as different species in which the elements are in varying oxidation state. Different arsenic and selenium species have different human toxicities, the inorganic species with a lower oxidation state being of the highest toxicity. It is of importance to know the concentration of the most toxic forms of the elements instead of their total concentration in order to evaluate the real human risks within the population. The present project aims at studying the possible schemes for separation and subsequent determination of the most toxic forms of arsenic and selenium. The separation schemes should be applicable at the sampling site. Thus the species will be separated immediately after sampling and the problems associated with their stability and possible losses and transformations during transportation can be eliminated. Recent scientific project: “Speciation of toxic arsenic and selenium species in waters and soil extracts with a view to developing field tests for their determination” Main fields of research: analytical chemistry, separation methods, speciation analysis, atomic absorption spectrometry Научна група „Рентгенофлуоресцентен анализ” Дейност:
Научни проекти: А) „Анализ на почви с помощта на рентгенофлуоресцентна спектрометрия”, 2008 – 2010 год, с подкрепата на Института по Обща и Неорганична Химия към Българска Академия на Науките;
Research group “Spectrophotometrical methods of analysis” Analytical chemistry of rhenium. Developing field tests for rhenium determination in plants with a view to biogeochemical indication of rhenium containing ores. Study of the mechanism of Re bioaccumulation in plants. Developing a method for rhenium bioextraction from soils and waste waters. Development of visual semiquantitative spot tests for analytical control of heavy metal traces in sea lye. Application of developed procedures to heavy metal control in the production of sea lye. List of projects, supported by BAS and RAS (Russian Academy of Sciences): 1.“Development of biogeochemical indicators for discovery of new ore deposits based on the analysis of rhenium content in green plants and study of the mechanism of rhenium bioaccumulation in plants”- joint project between BAS and RAS. 2.“Development of test methods for control of traces of Pb, Cd, Bi and Cu in Black Sea lye from Burgas and Pomorie region”- supported by BAS Research group “Atomic absorption spectrometry”
Research activity Flame atomic absorption analysis - pulse nebulization, atom traps. Electrothermal atomic absorption analysis – analysis of solutions, slurries, solid sampling, platform atomizers, coated graphite atomizers. Atomization efficiency. Study of interferences.
Fields of Research: noble gases, fluid inclusions, earthquake prediction, hydrothermal process, mass spectrometry General Subject: "Chemical Analysis of Natural Fluids" The following topics are covered: (i) Analysis of free and dissolved gases in mineral waters, with emphasision the noble gases helium and argon and their isotope ratios. An effective combination of microvolumetry and mass-spectrometry is utilized. (ii) Chemical analysis of fluid inclusions in minerals. Destructive methods such as decrepitation on heating or crushing are applied for opening of the inclusions. The cations in the inclusion water are determined by AAS or ICP-ES of water (acid) leaches. The volatiles (gases and water) are released in vacuum and analyzed mass-spectrometrically. The determination of the isotope ratios H/D and 16O/18O of the extracted water is also a topic of the investigation. The analysis of the inclusion fluids is supplemented with classical microscope techniques: determination of the temperature of homogenization as well as microcryometry aimed at evaluation of the total salinity (as NaCl). (iii) Kinetic studies of dehydration and decarbonatization of minerals (natural and synthetic) by a variety of the thermal analysis: Evolved Gas Analysis (EGA). The information obtained is of interest to chemists, geochemists, and mineralogists. |