Gas-liquid chromatographic determination of major constituents of Piper methysticum
A procedure is described for the quantitative determination of seven known major constituents in sun-dried roots, rhizomes and commercially powdered samples of Piper methysticum. A 3.0–8.0-g amount of powdered sample is extracted with chloroform in a Soxhlet apparatus for 6 h. After evaporation of solvent the extract (about 0.35 g) is dried at 100 °C for 2 h and then dissolved in chloroform to about 0.7%m/V concentration. The resulting solution is analysed by gas-liquid chromatography using dual 1.5 m × 4 mm i.d. glass columns, containing 3%m/m of OV-1 on Chromosorb W HP, and dual differential flame-ionisation detectors with nitrogen as carrier gas, the column temperature being 210 °C. There is no interference from the eight other trace constituents, non-polar low-boiling compounds or polar “tarry” material.