Method for analyte identification using isotachophoresis and a fluorescent carrier ampholyte assay

Area of Science:

• Analytical Chemistry
• Separation Science
• Biophysical Chemistry

Background:

• Isotachophoresis (ITP) is a separation technique.
• Carrier ampholytes can be used for analyte detection.
• Fluorescent labeling is common but can be limiting.

Purpose of the Study:

• To develop a novel method for identifying unlabeled analytes using fluorescent carrier ampholytes and ITP.
• To establish a signal analysis method based on fluorescent signal integration for quantitative analyte detection.
• To relate the normalized signal integral to analyte effective mobility for characterization.

Main Methods:

• Utilizing fluorescent carrier ampholytes in ITP for analyte displacement.
• Developing a signal analysis method based on the integration of fluorescent signals.
• Constructing calibration curves relating effective mobility to carrier ampholyte displacement using characterized analytes.
• Applying the method to determine mobility and dissociation constants of 2-nitrophenol and 2,4,6-trichlorophenol.

Main Results:

• A normalized signal integral was defined, accurately measuring carrier ampholyte displacement.
• This parameter was directly correlated with analyte effective mobility.
• Calibration curves were successfully generated using different leading electrolyte buffers.
• The method allowed for the extraction of mobility and dissociation constants for specific phenolic compounds without prior assumptions.

Conclusions:

• The developed method enables the identification of unlabeled analytes via fluorescent carrier ampholyte displacement in ITP.
• Analyte effective mobility and dissociation constants can be accurately determined from ITP experiments.
• This technique offers rapid, simultaneous analysis of multiple analytes based on their physicochemical properties with minimal sample preparation.