Quantitative analysis of serum methohexital by GLC using capillary column and nitrogen-selective detection

Area of Science:

• Analytical Chemistry
• Pharmacokinetics

Background:

• Methohexital is an anesthetic agent requiring accurate plasma concentration monitoring.
• Existing methods for methohexital quantitation may lack simplicity or sensitivity.

Purpose of the Study:

• To develop and validate a routine gas chromatographic method for methohexital quantitation in plasma.
• To establish a sensitive and precise assay for pharmacokinetic studies.

Main Methods:

• Gas chromatography with nitrogen-selective detection.
• One-step organic phase extraction of methohexital from plasma.
• Use of fused silica capillary columns for separation.

Main Results:

• The method demonstrated linearity from 0.125 to 50.0 µg/ml (r = 0.998).
• The assay sensitivity limit was 6 ng/ml in plasma.
• No interfering peaks were observed with co-administered drugs.

Conclusions:

• The developed method is suitable for routine, sensitive, and precise determination of methohexital in plasma.
• This assay facilitates the accurate determination of methohexital pharmacokinetic parameters in both pediatric and adult patients.