Static secondary ion mass spectrometry (SSIMS) of biological compounds in tissue and tissue-like matrices

Abstract

This paper presents results of a static secondary ion mass spectrometry (SSIMS) study of molecular, pseudo-molecular and structurally significant fragment ion peaks produced from an extensive list of biomolecules analyzed as neat residues and as components in biological matrices. This study defines realistic detection limits for analysis of representative pharmaceutical compounds incorporated into tissue or tissue-like matrices using state-of-the-art time-of-flight secondary ion mass spectrometry (TOF-SIMS) techniques. Detection limits on the order of 100–1000 parts-per-million (ppm) are observed under typical analytical conditions in which the analysis areas are approximately 200 micrometer (μm) in diameter and analysis depths are 1 to 2 monolayers. Representative secondary ion images of selected biomolecules are also presented and relationships between image resolution, mass resolution and detection sensitivity are discussed.