Fredenhagen, Andreas published the artcileEvaluation of the optimization space for atmospheric pressure photoionization (APPI) in comparison with APCI, COA of Formula: C20H17FO4S, the publication is Journal of Mass Spectrometry (2014), 49(8), 727-736, database is CAplus and MEDLINE.
The usefulness of atm. pressure photoionization (APPI) is difficult to evaluate for unknowns due to the fragmented literature. Specifically, the variation of dopants with a wide set of compounds or the use of APPI in the neg. mode have rarely been explored. Thirty compounds were selected that were not suitable for ESI with a wide variety of functional groups and investigated with atm. pressure chem. ionization (APCI) and APPI in the pos. and neg. ion modes. The influence of the mobile phase (eluents containing acetonitrile or methanol) and – for APPI – four different dopants (acetone, chlorobenzene, toluene, and toluene/anisole) were explored. Stepwise variation of the organic mobile phase allowed to elucidate the ionization mechanism. Atm. pressure photoionization was especially useful for compounds, where the M鈥? and not the [M + H]+ was formed. The dopants chlorobenzene and anisole promoted the formation of mol. ions M鈥? for about half of the compounds, and its formation was also pos. influenced by the use of mobile phases containing methanol. In the neg. ion mode, APPI offered no advantage toward APCI. Best results were generally achieved with the dopant chlorobenzene, establishing that this dopant is suitable for a wide set of compounds For one quarter of the compounds, significantly better results were achieved with mobile phases containing methanol for both APPI and APCI than those with acetonitrile, but only in the pos. mode. With either of the methods – APPI or APCI – about 10% of the compounds were not detected. Strategies to get results quickly with difficult unknowns will be discussed.
Journal of Mass Spectrometry published new progress about 59973-80-7. 59973-80-7 belongs to naphthyridine, auxiliary class Immunology/Inflammation,COX, name is Sulindac sulfone, and the molecular formula is C20H17FO4S, COA of Formula: C20H17FO4S.
Referemce:
https://en.wikipedia.org/wiki/1,8-Naphthyridine,
1,8-Naphthyridine | C8H6N2 – PubChem