Raman spectroscopy of C8, C18, CN, and DIOL chemically bonded TLC-type stationary phases

• Autorzy: Kowalska T. , Kowalik G. , Daniel P.
• Języki publikacji: EN

Abstrakty

EN

We have previously used high-power laser Raman spectroscopy to investigate selected aliphatic chemically bonded TLC-type stationary phases (C8, C18, CN, and DIOL) and determine the density of coverage of the inorganic silica matrix with organic ligands. It was established that the thermal energy of the neodymium laser light in the near infrared (NIR) caused irreversible damage to octyl, octadecyl, 3-cyanopropyl, and diol ligands and that this damage was most probably partial dehydrogenation, then aromatization of the aforementioned ligands. This resulted in a very intense, broad, and finely structured Raman band in the region from ca 2285 to 1130 cm–1 which enabled relatively easy quantification of the density of coverage of the silica matrix with the respective aliphatic ligands (which otherwise is hardly possible to assess). It is the aim of this paper to provide additional, although indirect, proof of our hypothesis that NIR irradiation is capable of structural transformation (basically, aromatization) of aliphatic chemically bonded ligands. Our approach to this issue consisted simply in acquiring additional Raman spectra of the same TLC-type C8, C18, CN, and DIOL stationary phases, this time by use of low-power argon–krypton ion laser Raman spectroscopy (emitting non-destructive 514.5-nm green radiation) and to check these spectra for the presence (or otherwise) of the spectacular and predominant Raman band in the region from ca 2285 to 1130 cm–1. The absence of this band would furnish indirect evidence for the destructive impact of the high-power neodymium laser. In fact, our new series of Raman spectra from the low-power argon–krypton ion laser contained no trace of the aforementioned band.

• Wydawca: University of Silesia in Katowice ; Akademiai Kiado
• Czasopismo: Acta Chromatographica
• Rocznik: 2000
• Tom: No. 10
• Strony: 85--96
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Kowalska T.

autor

Kowalik G.

autor

Daniel P.

• Institute of Chemistry, Silesian University, 9 Szkolna Street, 40-006 Katowice, Poland