Metal organic framework as a matrix for laser desorption/ionisation of environmental pollutants and other small molecules

Abstract

ABSTRACT Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a widely used method for analysing environmental pollutants and proteins. However, this technology has been limited in its ability to analyse small molecules (<700 Da) due to interference from conventional organic matrix background ions, leading to poor signal-to-noise ratios and reproducibility. In an effort to address this limitation, we have developed a new method for synthesising titanium metal organic frameworks (MOFs) as matrices for MALDI-TOF analysis. Specifically, we used a microwave-assisted facile synthesis method that results in smaller MOF particle sizes and requires less reaction time and simpler procedures. Our MOF, also known as NTU-9, was constructed using 2,5-dihydroxybenzoic acid as a ligand and titanium as a metal site. These constituents make NTU-9 highly efficient for photon absorption and target ionisation, allowing for improved MALDI-TOF analysis of diverse molecules, including environmental pollutants and other small molecules.