Determination of capsaicin in tissues and separation of capsaicin analogues by high-performance liquid chromatography.

Capsaicin, the pungent principle of chili peppers, and six analogues were characterized by reversed-phase high-performance liquid chromatography using isocratic methanol--water mixtures and UV detection. A highly sensitive method for the quantitative determination of capsaicin in animal tissues and blood has been developed. Using a reversed-phase column and acetonitrile--water mixtures for elution, 3 ng of capsaicin could be measured by fluorimetric detection at an excitation wavelength of 270 nm and an emission wavelength of 330 nm. Acetone extraction of tissue resulted in a recovery of approximately 90%. Extraction and determination of capsaicin in rat brain, spinal cord, liver and blood after i.v. administration is given as an example.