Gas chromatographic determination of l-ephedrine and dl-methylephedrine

가스크로마토그라피에 의한 l-에페드린과 dl-메칠에페드린의 정량

The determination method of l-ephedrine and dl-methylephedrine by gas chromatography was developed, using reactive alkaline precolumn packed with celite 545 containing KOH. Symmetrical peaks were achieved under the condition, inlet temperature, $180^{\circ}C$-$230^{\circ}C$; column temperature, $180^{\circ}C$- $160^{\circ}C$; carrier gas flow rate, 30ml/minute. The peaks of the salts coincided with those of bases. When this method was applied to preparations, using d-dimethylaminobenzaldehyde as inner standard, good results were obtained. The relative retention times of l-ephedrine and dl-methylephedrine to p-dimethyl aminobenzaldehyde were 0.50 and 0.65 respectively.