Capillary electrophoresis with post-column addition of terbium and sensitized lanthanide-ion luminescence detection for the determination of diflunisal and salicylic acid
✍ Scribed by Milofsky, Robert ;Bauer, Eve
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 505 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0935-6304
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✦ Synopsis
Abstract
A detection scheme based on the Post‐column addition of terbium followed by sensitized luminescence detection has been developed. Two model Compounds‐ saliculic acid and diflunisa‐ were separated by capillary electophoresis in an alkaline phosphate buffer. A Solution containing terbium and CTAB was added post‐column via a “home‐built” reactor resulting in the rapid fromation of the strongly luminescent terbium‐salicylic acid and terbium‐diflunisal complexes in a reaction capillary. Following complexationn in the reaction capillarty, the 325 nm line from a HeCd laser was used to excite the analytes which efficiently transfer their energy to terebium. Resuulant luminescence of terebium was liner of 2 orders of magnitude. This novel and practical system enables the detection of micromolar concentrations of diflunisal and salicylic acid‐ a 10 fold improvement over UV absorbance detection in the same system. Post‐column addition of terbium also eliminates the problems associated with strong adsorption of the lanthanide ion to the silica walls of the separation capillary and the formation of metal‐ligand complexes with different coordination numbers.