Potential of Liquid Extraction Surface Analysis Mass Spectrometry (LESA—MS) for the Characterization of Polymer-Based Materials

Abstract

Liquid extraction surface analysis mass spectrometry (LESA -MS) is a direct analysis method suitable for the analysis of polymers. It is based on a fast and efficient extraction of polymer components, such as non-intentionally added species (NIAS), post-polymerization residues, or additives, and residues resulting from specific uses followed by their MS detection. In comparison with batch methods, it is a “green” method, using negligible volumes of organic solvents, and it is cost-effective, avoiding lengthy sample preparation procedures. It can be used for the detection of known molecules (targeted analysis), identification of unknown species (exploratory analysis requiring MS/MS) and semi-quantative analysis, if standards are available. The to-date applications of LESA-MS in the field of polymer science are reviewed and critically discussed taking into account the hands-on experience from the authors’ laboratory. Future possibilities of LESA applications are highlighted.

Discontinuously Dewetting Solvent Arrays: Droplet Formation and Poly-Synchronous Surface Extraction for Mass Spectrometry Imaging Applications

“…The omniphobic coating employed in this study enables different solvents to be used to form the droplets. In this way, there is potential to alter the selectivity of the analytes being extracted through different extraction conditions . Solvent choice may also mitigate matrix effects and enhance the sensitivity, especially in complex environments (e.g., in vivo tissue profiling).…”

Rapid authentication of agarwood by using liquid extraction surface analysis mass spectrometry (LESA‐MS)

“…An important point to be considered while carrying out LESA is the extraction efficiency of samples. The main limitation of the new approach is the necessity to create a micro‐junction, though it is difficult to extract on the rough, wettable or absorbent surfaces 18 . Considering the efficiency of extraction, we have tried pure water and single solvent extraction systems (acetonitrile, methanol, ethyl acetate) respectively, but diffusion occurred easily when the single solvent was released by the pipette tip on the surface of the sample, making it difficult to gather together to form an extracted droplet.…”

“…When using LESA‐MS, only a minimum amount of solvent is required, and the extraction can be performed on the surface of samples directly without sample pretreatment under open atmospheric conditions. Moreover, the whole process only takes about 1 to 2 min 18 . This approach has a wide range of applications in metabolite, lipid, protein, carbohydrate analysis, and drug distribution from tissue sections 19–23 .…”

Liquid extraction surface analysis‐mass spectrometry: An advanced and environment‐friendly analytical tool in modern analysis

“…Until now, these approaches have only been able to analyse tiny molecules (lipids and metabolites), but LESA‐MS can analyse complete proteins in bacteria [29]. High temperatures are required for techniques like DESI and direct analysis in real time, which may cause degradation of the sample, such as polymers; degradation products might thus be discovered, altering the analysis of the material's inherent impurities [3]. Because the presence of the immobilising agent can give false positive results, the indirect evaluation of non‐covalent interactions between the protein and the ligands through detection of the ligand molecules by DESI is not totally conclusive [39].…”