Approaches for the analysis of low molecular weight compounds with laser desorption/ionization techniques and mass spectrometry

Abstract

This review summarizes various approaches for the analysis of low molecular weight (LMW) compounds by different laser desorption/ionization mass spectrometry techniques (LDI-MS). It is common to use an agent to assist the ionization, and small molecules are normally difficult to analyze by, e.g., matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) using the common matrices available today, because the latter are generally small organic compounds themselves. This often results in severe suppression of analyte peaks, or interference of the matrix and analyte signals in the low mass region. However, intrinsic properties of several LDI techniques such as high sensitivity, low sample consumption, high tolerance towards salts and solid particles, and rapid analysis have stimulated scientists to develop methods to circumvent matrix-related issues in the analysis of LMW molecules. Recent developments within this field as well as historical considerations and future prospects are presented in this review.

3D Mass Spectrometry Imaging Reveals a Very Heterogeneous Drug Distribution in Tumors

“…Another positive effect is that the spatial resolution depends only by instrumental specification like laser spot diameter and not by the crystallization of the matrix16. Metallic NPs have been largely employed in MALDI experiments1718192021 and in particular, TiO2 nanoparticles have been used for distribution studies of small endogenous molecules2223.…”

Effect of polydimethylsiloxane (PDMS) coating on TiO2-based MALDI matrix for dimethyl methylphosphonate (DMMP) analysis

“…Although much remains unclear regarding the mechanistic details of the MALDI process, it is obvious that the organic matrices cocrystallize with analyte molecules and induce their ionization and desorption upon laser irradiation [11][12][13][14][15]. However, use of organic matrices for small molecule (<500 Da) analysis can be limited due to the interference by fragmentation of organic acid matrices upon laser irradiation yielding background signals at low masses [16][17][18]. To overcome this problem, several alternative matrices, such as carbon nanotube [19][20][21], surfactant-mediated matrix [22][23][24], graphene [25,26] and metal oxides [27][28][29][30][31][32] have been investigated.…”

Gold nanoparticle-enhanced target for MS analysis and imaging of harmful compounds in plant, animal tissue and on fingerprint

“…The use of gold nanostructures in laser desorption/ionization (LDI) mass spectrometry (MS) of low molecular weight compounds was covered recently in an excellent review by Bergquist and coworkers [1]. Gold nanostructures have been used more frequently since publication of the pioneering work by Russell [2], who presented methods of preparation of size-controlled gold nanostructures.…”