Investigation on separating conditions of nicotine homologues by gas chromatography

Various factors in gas-chromatographic analysis of tobacco alkaloids, including sort and amount of stationary liquid, column temperature, flow rate, sort and grain size of solid support, were examined on their influences on the height of theoretical plates and the sensitivity of determination, and the operating conditions in the separation of nicotine homologues of analogous properties were investigated. The height of theoretical plates was minimized on a definite flow rate (ca. 100 ml/min.), and the value decreased hence the column efficiency increased with increasing amount of stationary liquid (PEG 6000) provided that its amount was 324%. With the flow rate minimizing the height of theoretical plates, the latter showed a minimum at 160180°C of column temperature. C 22 is preferred to Celite as a solid support, and the smaller particles were more preferable. The amount of sample to be injected should be smaller to obtain the largest number of theoretical plates. The recommended conditions for the separation of nornicotine and myosmine were as follows: the amount of stationary liquid 24%, temperature 180°C, flow rate 80 ml/min., injected amount 1 μl and column length 2 m.