Dynamic Analysis of major elements in biological tissue validating quantification of trace life elements in MeV ion beam microscopy

Abstract

MeV ion microprobe measurements of the lesser and trace life element concentrations in biological tissues are challenging because of complex spatial inhomogeneities in these types of samples. Measurements on ex vivo tissue sections require determination of the matrix element composition and the tissue section thickness. For these reasons, in this work, we adapted the Dynamic Analysis approach known from literature, to interpret the MeV ion microscopy data to determine concentrations of H, C, O, and N as well as the thickness of different tissue regions in Non Human Primate (NHP) mesenteric lymph node section. The results showed no strong variations of the matrix element contents regardless of section thickness variations in the tissue. The matrix information was used to quantify total-Ca molarities and a significant $\sim$30 mM Ca concentration hotspot was observed at the edge of sinus structure in the mesenteric lymph node as compared to the 3-4 mM total-Ca levels in the surrounding tissues. Thus, MeV ion microprobe imaging combined with dynamic analysis comprise a novel chemometric approach paving a way for quantitative analysis of similarly complicated animal and plant biological tissue sections.