Instrumental Neutron Activation Analysis of biological materials Junior

Instrumental Neutron Activation Analysis of biological materials Junior researcher Atanas Vasilev Sofia University “St Kliment Ohridski” Sector of neutron activation analysis and applied investigation(SNAAPI) FLNP, JINR Bulgarian Academy of Sciences (BAS)

Contents What is Instrumental neutron activation analysis (INAA) ? Definition, Characteristics , Advandateges and Disadvantages Theory and Practice of INAA Main physical principals , Instrumentation , Procedure of INAA at SNAAPI Application of Instrumental activation analysis For biological materials in particular , Fields of investigation, Results

What is INAA ? Analytical technique allowing the Qualitative and Quantitative determination of the Elemental content of the studied sample Sample INAA Elemental content RESULTS What elements are present in the sample The concentration of each element (mg. kg-1)

Physical principles Activation Irradiation of sample with n Neutron capture Radioactive isotope Measurement Sample emits γ Hp. Ge detector Analysis Eγ ~ type of nucleus A~ concentration

Detected elements

Some classification of detected elements in accordance to human health

Containers Pneumatic system IBR-2 Detectors

Examples of research on samples of biological origin Medicinal plants / Herbs Human tissues Quality control of food Regulatory document Maximal permissible concentrations Toxic elements Essential elements Bone cancers relation to elemental content of the bone Hair as an indicator of diet in contaminated regions Biomonitoring Moss / Evaluate airpolution Super absorbers / Soil pollution Anthropological activities Natural nano materials Bacteria as factory of nano particles Cheap and effective

Mg σ% Al σ% S σ% Cl 2790 3 237 3 1740 25 5580 Convolvulus althaheodis 2340 3 72 3 3560 25 11000 Pallenis spinosa 1740 3 95 3 1450 25 6930 Centaurium erythraea Rafn 1540 3 331 3 2170 25 2600 Lavandula viridis 4130 3 144 3 2060 25 2130 Rubus ulmifolius 2010 3 339 3 2380 25 2030 Thymbra capitata 1940 3 66 3 2400 25 7740 Aristolochia baetica 2860 3 467 3 1830 25 1130 Rosmarinus officinalis (leaf) 1580 3 272 3 1340 25 1680 Rosmarinus officinalis (stem) 6890 3 405 3 17200 25 8940 Equisetum arvense 1100 3 27 3 5820 25 5760 Cynara humilis 1270 3 158 3 3820 25 2360 Lavandula pedunculata 2490 3 412 3 7530 25 6780 AVARAGE 2000 Name 80 3000 2000

Primary Method “ A primary method of measurement is a method having the highest metrological properties, whose operation can be completely described and understood, for which a complete uncertainty statement can be written down in terms of SI units” [1] -fully physically and chemically understood -measurement equation can be written down -uncertainty equation can be written down -values of all the parameters are in SI -Traceability Primary Ratio Method “A primary method of measurement that measures the value of a ratio of an unknown to a standard of the same quantity; its operation must be completely described by a measurement equation” [2]

Advantages and capabilities Number of elements detected Theoretically up to 80 elements In our case up to 40 elements Low detection limits Depending on the element From mg. kg-1 to ng. g-1 No need for chemical treatment of the samples = no contamination High accuracy and precision Traceability and reputability of the results Simultaneous results for many elements Well established “mature” technique All the “underwater stones” are known Low uncertainty of the results For different elements ranges from 1% to 30% percent

Disadvantages of INAA No information on the chemical form of the elements What molecules does the elements contribute to Expensive instrumentation Neutron source, detectors, infrastructure etc. Need of Experimental reactor Work with radioactive materials Need of special rooms , equipment and training

Conclusions INAA posses high metrological capabilities Good for investigation on the elemental content of biological materials due to its ability to detect great number of relevant chemical elements Necessity for combination with other analitical techniques that give information on the chemical form of detected elements

Thank you for the attention