GLC determination of caffeine in plasma using alkali flame detection

Area of Science:

• Analytical Chemistry
• Pharmacokinetics

Background:

• Accurate quantification of caffeine in biological samples is crucial for understanding its pharmacokinetics.
• Existing methods may lack the required speed, specificity, or sensitivity for certain applications.

Purpose of the Study:

• To develop and validate a rapid, specific, and sensitive gas-liquid chromatography (GLC) assay for determining caffeine concentrations in plasma.

Main Methods:

• Gas-liquid chromatography (GLC) with alkali flame-ionization detection.
• Mepivacaine used as an internal standard.
• Sample preparation involved alkalinization and chloroform extraction.

Main Results:

• Linear standard curves were achieved in the 0.25-10.0 microgram/ml range.
• Absolute sensitivity was 0.1 microgram/ml from a 1.0-ml plasma sample.
• The method demonstrated good precision with a relative standard deviation of 5.2% for a 2.0 microgram/ml standard.

Conclusions:

• The developed GLC assay is rapid, specific, and sensitive for plasma caffeine quantification.
• This method is suitable for pharmacokinetic studies, including time-concentration analyses in human and animal plasma.