Laboratory for Elemental Microanalysis

O-022

 

Members of the Laboratory

Head: Profesor Ivica Orlić

         Assistant prof. Darko Mekterović

           
           Marija Čargonja

 

  Prof. Ivo Orlić
Full professor
 
Curriculum vitae (.pdf)
 
Office: O-011
Phone: (051) 584 620
E-mail: ivo.orlic@uniri.hr

 
 
     
  Dr. Darko Mekterović
Assistant professor
 
Curriculum vitae (.pdf)
 
Office:O-005
Phone: (051) 584 616
E-mail:darko.mekterovic@phy.uniri.hr
 
     
   
Marija Čargonja
Junior researcher
 
Curriculum vitae (.pdf)
 
Office: O-S13
Phone: (051) 584 623
E-mail: mcargonja@uniri.hr
 

                                       

SCIENTIFIC RESEARCH
 
The Laboratory for Elemental Microanalysis is equipped with nuclear analytical techniques based on X-ray spectroscopy, primarily for studying patterns relevant to environmental protection, but also for studying archaeological specimens and samples related to cultural heritage; for the first time in this region, non-destructive, multi-elemental analytical techniques enabled identification of the sources and intensity of individual sources of anthropogenic atmospheric pollution.
 

The principal analytical technique proposed to be used in the Laboratory is X-ray Fluorescence or XRF. XRF is well established analytical technique that has been around for many decades. It has been used in various fields of science and applications wherever fast, multi-elemental analysis was required. The excitation of the sample is typically done by means of an x-ray radioactive source or more commonly by an X-ray tube.  Once sample is irradiated, characteristic x-rays are emitted by all elements present in the sample. These x-rays are detected by special detectors, measured and analyzed. Measured intensities of the characteristic x-rays will enable us to calculate concentration of each element of interest in the sample. 

Portable micro-XRF system has a number of advantages: the assembly is relatively small and therefore portable (useful for field exploration), it provides a powerful source of primary X-ray excitation beam and therefore fast analysis and last but not least, it is relatively inexpensive.   
Nuclear analytical techniques have many advantages over the conventional analytical techniques, to name only few:
  • Techniques are multielemental (typically all elements from Si to U can be analysed in a single run),
  • Spectra are relatively simple to interpret, therefore quantitative analysis fast and accurate,
  • Analysis is non-destructive,
  • The material to be analysed may be minute (micron size) and in a variety of forms, i.e. solid, liquid, powder, slurry, gas, etc.,
  • Sample preparation is minimal often requiring only cleaning,
  • Wide dynamic range, i.e., concentrations from 100% to less than 1 part per million (ppm) can be analysed in a single run



Aerosol pollution monitoring
XRF and especially PIXE methods are ideally suited for aerosol analysis. Multi-elemental capabilities combined with the ease of sample preparation, small sample mass available and non-destructiveness are capabilities that make PIXE the method of choice for aerosol analysis. On the other hand, in Rijeka with nearly 200,000 inhabitants, several refineries and power plants and extended calms that are becoming more and more common, the air pollution is often reaching critical levels. Although Government agencies do monitor air pollution on regular basis, an independent and continuous monitoring of air quality would be highly desirable – especially in the light of Croatia joining European Union within several years. In August 2013, the Laboratory for elemental microanalysis has started with a systematic collection of PM2.5 particulate matter in Rijeka, Croatia. Until now, more than 200 samples have been collected on stretched teflon filters. Aerosol sampler is designed to collect fine aerosols, i.e. aerosol particles with the (dynamic) diameter of 2.5 micrometers or less. This is so called anthropogenic component of aerosol pollution and represents the predominant component in most urban environments caused by manmade, mainly fissile fuel burning processes (traffic, power plants, industry, etc.). The results of NAT analysis of such samples enables scientists to identify 'fingerprints' of major pollutants and from there to pin-point the major 'culprits' and sources of air pollution in the area. The principal investigator of this Laboratory has many years of international experience in this field (Singapore and Sydney) which is obvious from a large number of relevant scientific publications.


PUBLICATIONS

1. Ivošević, Tatjana; Mandić, Luka; Orlić, Ivica; Stelcer, Eduard; Cohen, David., Comparison between XRF and IBA techniques in analysis of fine aerosols collected in Rijeka, Croatia, Nuclear Instruments and Methods in Physics Research B (0168- 583X) 337 (2014); 83-89

Fine aerosol samples analysis in Rijeka, Croatia, poster from European Conference on Spectrometry, Bologna 2014