A small quantity of the oils is analyzed by gas chromatography under specified conditions on a packed column. The safrole and cis- and trans-isosafrole contents are determined by using the internal standard method. As stationary phase are used polydimethylsiloxane, or polyethylene glycol 20000. Operating temperatures: Oven: isotherm about 100 °C when using polydimethylsiloxane; isotherm about 125 °C when using polyethylene glycol 20000. Injection system and detector: about 170 °C.