Detection of Bilirubin Using Surfactant Fluorescence Enhancement and Visible Laser Fluorometry

Abstract

Improvements on detection limits for the measurement of unconjugated and conjugated bilirubin in aqueous solutions using surfactant fluorescence enhancement and visible laser fluorometry were investigated. To maximize the fluorescence signal, commonly used surfactants were employed to enhance the fluorescence quantum yields of these bilirubin molecules and one of the visible lines of an argon ion laser was used for fluorometric excitation; to minimize optical noise, a unique optical fiber flow-cell was employed. Relative and absolute limits of detection for the micelle-bound unconjugated and conjugated bilirubin were in the sub-micromole per liter and sub-nanogram range, respectively. These capabilities should be important for the potential use of surfactants in flow injection analysis or micellar liquid chromatography for the determination of bilirubin species in biological materials.

Key Words:

• Bilirubin determination
• surfactant fluorescence enhancement
• visible laser fluorometry