Paper-assisted thermal ionization

Paper-assisted thermal ionization Observation of reactive intermediates Pei et al. [394]... 

Pei, J., Kang, Y, Huang, G. (2014) Reactive Intermediate Detection in Real Time via Paper Assisted Thermal Ionization Mass Spectrometry. Analyst 139 5354-5357. 

Figure 11.6 Chemical reactions accelerated under heating for real-time MS monitoring, (a) Schematic diagram of the paper-assisted thermal ionization setup. (A) Heated metal probe, (B) filter paper, and (C) home-made pipette tip. (b) Proposed mechanism of the Eschweiler-Clarke reaction [58]. Reproduced from Pei, j., Kang, Y., Huang, C. (2014) with permission of the Royal Society of Chemistry.

Several original papers must be mentioned that deal with mass spectrometric techniques which the numerous reviews do not comprise. Kaufmann and coworkers268,288 studied the mass spectrometric analysis of carotenoids and some of their fatty acid esters using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry and its post-source-decay (PSD) variant. Some advantages concerning the thermal instability and limited solubility were discussed, but the fragmentation paths of the carotenoid cations were found to be essentially the same as those observed with conventional techniques. 

Three years earlier, in 2000, Scrivens and Jackson published a review paper with the same title [5], in which revolutionary technical advances in the field were described. In their words, before the so-called revolution, The majority of mass spectrometric studies of polymer systems required optional extraction of the additives from the polymer followed by a chemical or thermal degradation of the polymer itself. Due to partial degradation, the authors make a distinction between direct measurements and indirect measurements [5]. The mass spectra of many synthetic polymers are discussed, but they limit their review to spectra recorded using three ionization techniques, namely field desorption (FD), electrospray ionization (ESI), and matrix-assisted laser desorption/ionization (MALDI). For MS of synthetic polymers prior to the revolution, the authors refer the reader to other sources. 

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