Co-NC as adsorbent and matrix providing the ability of MALDI MS to analyze volatile compounds

Abstract

Traditional matrix does not allow matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) to analyze volatile compounds, because volatile analytes may vaporize during the sample preparation process or in the high vacuum circumstance of ion source. Herein, we reported a Co and N doped porous carbon material (Co-NC) which were synthesized by pyrolysis of a Schiff base coordination compound. Co-NC could simultaneously act as adsorbent of volatile compounds and as matrix of MALDI MS, to provide the capability of MALDI MS to analyze volatile compounds. As adsorbent, Co-NC could strongly adsorb and enrich the volatile compounds in perfume and herbs, and hold them even in the high vacuum circumstance. On the other hand, Co-NC could absorb the energy of the laser, and then transfer the energy to the analyte for desorption and ionization of analyte in both negative and positive ionization modes. Additionally, the background interferences were avoided in the low-mass region (< 500 Da) when using Co-NC as matrix, overcoming the challenges of MALDI MS analysis of small molecule compounds. In summary, Co-NC as matrix tremendously extended the application of MALDI MS.