A simple and rapid method was developed to determine the presence ofnicotinamide in tonic drinks using the megapore semi-polar column (CP-Sil 8 CB, 30m x 0.53 mm) with direct injection gas chromatography. Direct quantitative analysisof nicotinamide in amino acid drinks, vitamin drinks, essence of chicken and tonicdrinks was carried out without any sample pretreatment procedure. Water solublecompound 1,9-nonanediol was used as an internal standard. The detection limit fornicotinamide was 2-5 μg/mL. Recovery studies were performed using 1 mL ofvitamin drink and tonic drink, each spiked with nicotinamide at 105.5, and 211.0 μg,respectively. The recoveries were found in the range of 94~99% and 93-108%,respectively. The coefficients of variation being less than 9.8%. Forty-two commercialamino acid drinks, vitamin drinks, essences of chicken and tonic drinks were analyzedwith this method. The nicotinamide contents were found as: 131-246, 24-112, 0-134and 0-263 μg/mL, respectively. These results indicated that, one bottle each of theamino acid drink, vitamin drink, essences of chicken and tonic drink containnicotinamide levels of : 39-74, 5-22, 0-10 and 0-21 mg/bottle. The results also showedthat in 12 out of 4 of commercial amino acid and vitamin drinks, the nicotinamideexceeded the ROC's acceptable daily intake (RNDA, 14.4 mg) level; and 3 out of 10commercial tonic drinks exceeded the ROC's RNDA level for nicotinamide.