On-capillary raman spectroscopy of nucleoside/borate complexes separated by isotachophoresis

Abstract

On-capillary normal Raman spectroscopy with 532 nm excitation is Ž. used as a detection method for capillary isotachophoresis ITP of the nucleosides: adenosine, cytidine, guanosine, and uridine. The compounds are separated as their borate complexes between leading electrolyte 0.1 M Cl y , pH 7.5, and terminating Ž. y electrolyte 0.1 M B OH , pH 10. The Raman spectra of the nucleosiderborate 4 complexes are presented. Additionally, Raman spectra are obtained from sepa-X Ž. rated adenosine and adenosine 5-triphosphate ATP. Starting concentrations in the range 5.0 = 10 y6 ᎐5 = 10 y4 M are employed. Preconcentration factors of at least 10 3 are observed.

Raman Spectroscopy

“…Michael Morris' group and collaborators have reported on the combination of isotachophoresis and Raman spectroscopy. Their work included both capillary systems (41,42) and microfabricated chip devices (43). UVvisible or fluorescence are the standard detection methods for isotachophoresis, however, the use of Raman facilitated simultaneous collection of qualitative and quantitative data.…”

Recent progress in capillary isotachophoresis

“…ITP with on-capillary Raman spectroscopy detection was used to separate the nucleosides adenosine, cytidine, guanosine and uridine as borate complexes (LE: 100 mM chloride, pH 7.5; TE: 100 mM borate, pH 10) [74]. The same technique using a fiberoptic Raman probe fitted with a microscope objective was used to obtain on-line spectra of adenosine 5¢-monophosphate, cytidine 5¢monophosphate, guanosine 5¢-monophosphate and uridine 5¢monophosphate from their separated ITP zones (LE: 100 mM sodium sulfate; TE: 100 mM MOPS) [75].…”