The possibility of direct analysis of biological tissues of a few milligrams by SR XRF method
Development and improvement of analytical methods to explore the element and microelement composition of biological tissues enables obtaining additional information on functioning of systems of organs and tissues. It is the information on the multi-element composition of biopsy material of living organisms that is relevant. Since this material always has very low weight, 4 mg to 0.5 mg of dry weight, such amount of sample material cannot be directly explored by the conventional non-destructive methods of analysis. The works performed use the unique properties of synchrotron radiation, which enable analysis of small-weight samples (a few milligrams), which is virtually impossible with the conventional methods. The SR XRF method enables analysis of small-weight samples and selection of optimal conditions for analysis of the elements. For nine years, the experimental station for X-ray fluorescence analysis (VEPP-3, BINP) has been involved in joint systematic exploration with Meshalkin Research Institute of Blood Circulation Pathology. About 1000 samples of the vascular system in patients with different pathologies have been analyzed: congenital heart disease, coronary heart disease, dilated cardiomyopathy (heart transplant), aortic aneurysm, etc. A new sample-preparation method for direct analysis of biopsy material weighing to 0.5 mg was developed. A technique of analysis of fragments of biopsy and surgical samples by K-lines of S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Kr , Rb, Sr, and Mo was developed. The results of the determination of the elemental composition of fragments of biopsy and autopsy samples of cardiovascular disease by the SR XRF method gave a method of evaluating the functional state of the heart. It can be used in clinical practice for pre-testing in pathology of heart transplant and in aortic dissection.