Institute of Catalysis
Bulgarian Academy of Sciences

Institute of Catalysis
Bulgarian Academy of Sciences

Acad. G. Bonchev St., Bldg. 11,
Sofia 1113, Bulgaria

Tel: +359 2 9793563;
fax: +359 2 9712967;
e-mail: » Departments > Laboratories Български

Laboratory of Design and characterisation of catalytic materials
Center of EPR spectroscopy

Welcome to the page of Center of EPR spectroscopy!

Electron paramagnetic resonance (EPR) spectroscopy, also known as Electron spin resonance (ESR), is a method that obtain information on the structure and properties of systems with unpaired electrons (paramagnetic systems). These unpaired electrons often play a key role in the catalytic, magnetic, chemical and physical properties of the materials. EPR is a technique for understanding the local atomic environment of unpaired electrons in materials. With EPR are investigated: free radicals and defects generated in the substances by an external influence (irradiation with ionizing radiation, heat treatment, etc.); paramagnetic transition metal ions, stable radicals in chemistry and biology, short lived species etc. The application field of EPR is very wide and includes not only investigation of solid state, but also liquids and gases. The EPR can be used also for quantitative determinations in dosimetry and dating. The EPR method has high sensitive and resolution. It can find paramagnetic particles with concentration 10-11-10-12 M. This method is non-destructive.
We currently work on two topics:

  1. Applied EPR spectroscopy included: EPR dosimetry, identification of free radicals in irradiated foodstuffs and medicines, study of thermally induced free radicals in the foodstuffs, determining the antioxidant properties of foods and natural products.
  2. Application of EPR in catalysis for studying the oxidation state of the transition metal ions: Cu (II), Mn (II), V (IV), Fe (III), Cr (III), Cr (V), Co (II), Rh (II), Ni (II), Mo (V), Ti (I), Ti (III) etc.

The Center for EPR spectroscopy performed service samples.


  • JEOL JES – FA100 ESR spectrometer working in X – band; two ranges of temperature are available: 50°C to 150°C and -120°C to 50°C.
  • BRUKER ER200 D-SRC spectrometer working in X- and Q-bands; variable temperature attachments working in the range 100-500 K and 3.8-300 K; ENDOR attachment (under PC control) with 300 W power amplifier working in the frequency region 0.5-36 MHz
  • ADANI PS100X ‘mini’ EPR machine (fully under PC control) operating in X-band with attachments for variable temperature (100-500 K)
  • BRUKER ER420 spectrometer working in Q – band.
  • Carl-Zeiss UV-VIS spectrophotometer supplied with home made variable temperature accessory

Youngh and energetic people (students and PhD students) are welcome to join us. Sense of humor and persistence are always helpfull.


Yordanka Karakirova
Associate Professor, PhD

(+359 2) 9793591



Nicola Yordanov, Professor, DSc, Associated Member of Institute of Catalysis
Katerina Aleksieva, Assistant Professor, PhD
Ralitsa Mladenova, Assistant Professor, PhD


Infrastructure project

  • “Building the base of National centre of EPR spectroscopy” – Nat. Sci. Fund – IRNI 05 - 2007/2008.

Research projects

  • “EPR investigation on the generation and stability of radiation induced free radicals in gamma-irradiated foodstuffs. Comparative studies by the method of DNA comet assay”, Nat. Science Fund ТК-Х-1604 - 2006-2010.
  • “Study of the structure and dosimetric properties of high-energy irradiated saccharides” – University of Gent, Belgium 2006-2009.



10 December 2018
Конкурс zа назначаване на длъжност „изследовател“ по проект BG05M2OP001-1.001-0008-С02

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