Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in elemental imaging of biological tissues and in proteomics

Abstract

Of all the inorganic mass spectrometric techniques, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) plays a key role as a powerful and sensitive microanalytical technique, enabling multi-element trace analysis and isotope ratio measurements at the trace and ultra-trace level in the life sciences. LA-ICP-MS was used to produce images of detailed regionally specific element distribution in thin sections of tissue from different parts of the human brain. The quantitative determination of copper, zinc and other elements distributed in thin slices of human brain samples was performed using matrix-matched laboratory standards. Imaging mass spectrometry provides new information on the spatially inhomogeneous element distribution in thin sections of human tissue, for example of different brain regions (e.g., insular region) or brain tumour tissue. The detection limits obtained for Cu and Zn determination in tissue sections were in the sub-µg g–1 range. Possible strategies will be discussed for applying LA-ICP-MS in brain research and the life sciences, including the imaging of thin slices of brain tissue in order to obtain element distributions or applications in proteome analysis in combination with MALDI-MS to study phospho- and metal-containing proteins.