Ambient characterization of synthetic fibers by laser ablation electrospray ionization mass spectrometry

Abstract

Direct analysis of synthetic fibers under ambientconditions is highly desired to identify the polymer, the finishesapplied and irregularities that may compromise its performanceand value. In this paper, laser ablation electrospray ionizationion mobility time-of-flight mass spectrometry (LAESI-IMSTOF-MS) was used for the analysis of synthetic polymers andfibers. The key to this analysis was the absorption of laser lightby aliphatic and aromatic nitrogen functionalities in thepolymers. Analysis of polyamide (PA) 6, 46, 66, and 12 pelletsand PA 6, 66, polyaramid and M5 fibers yielded characteristicfragment ions without any sample pretreatment, enabling theirunambiguous identification. Synthetic fibers are, in addition,commonly covered with a surface layer for improved adhesionand processing. The same setup, but operated in a transient infrared matrix-assisted laser desorption electrospray ionization (IRMALDESI)mode, allowed the detailed characterization of the fiber finish layer and the underlying polymer. Differences in finishlayer distribution may cause variations in local properties of synthetic fibers. Here we also show the feasibility of massspectrometry imaging (MSI) of the distribution of a finish layer on the synthetic fiber and the successful detection of local surfacedefects