本研究建立了直接注入氣相層析分析市售保健飲料、口服液及感冒藥液等液體樣品中菸鹼醯胺、對羥苯甲酸酯類及咖啡因之快速、簡便之同步測定方法。採用直接注入之方式，以中間極性之CP-Sil 24 CB 管柱（30 m × 0.53 mm,1.5 mm）同步分析定量上述液體樣品之菸鹼醯胺、對羥苯甲酸酯類及咖啡因，選擇水溶性之1,9-壬二醇（1,9-nonanediol）為內標準，三者之最低檢出濃度約為2 μg/mL 左右。分別添加100 μg 之菸鹼醯胺、對羥苯甲酸丁酯及咖啡因於1mL 維生素B 飲料、口服液及感冒藥液檢體中，直接取樣注入GC 分析，其回收率分別為：菸鹼醯胺， 96 、102 及105%，變異係數在7.2%以下；對羥苯甲酸丁酯， 105 、95 及107%，變異係數在8.3%以下；及咖啡因， 101 、95 及104%，變異係數在7.5%以下。以本方法分析市售不同廠牌之保健飲料、口服液及感冒藥液等液體樣品共52 件之菸鹼醯胺、對羥苯甲酸酯類及咖啡因含量。結果顯示，菸鹼醯胺含量分別為20.3-241.7 、0-210.7 及0-246.8 mg/mL ；對羥苯甲酸異丁酯含量分別為0-54.1 、0-42.9 及0-134.1 μg/mL ；對羥苯甲酸丁酯含量分別為0-106.8 、0-120.1及0-184.6 μg/mL 及咖啡因含量分別為0-433.2 、0-80.7 及472.3-1742.9 μg/mL 。以上結果顯示，菸鹼醯胺若換算為每瓶之總含量，則18 件保健飲料中有6 件， 12 件口服液中有2 件及22 件感冒藥液中有2 件超過國人每日平均建議攝取量（RNDA=14.4 mg）。在防腐劑含量方面，大部分商品均未標示含“防腐劑”， 52 件樣品中有25 件檢測出含對羥苯甲酸異丁酯或丁酯，其中有4 件超過CNS 標準（100 μg/mL）；而在咖啡因含量方面，保健飲料及口服液均未標示咖啡因含量， 30 件樣品中有27 件檢測出含咖啡因，顯然不符CNS 之規定。

　　　　　A simple and rapid method was developed to simultaneously determine thenicotinamide, paraben as well as caffeine by using megapore immediate-polar column(CP-Sil 24CB, 30 m ’0.53 mm, 1.5mm) with direct injection gas chromatography.Direct quantitative analysis of nicotinamide, paraben esters and caffeine in healthdrinks, tonic drinks, and cold formulas was carried out without any samplepretreatment procedure. The water soluble compound 1,9-nonanediol was used as aninternal standard. The detection limit for nicotinamide, paraben esters and caffeinewas 2mg/mL. Recovery studies were performed using 1 mL of vitamin B drink, tonicdrink and cold solution, each spiked with nicotinamide, paraben esters and caffeine at100.0mg, respectively. The recoveries for nicotinamide were 96, 102 and 105%,respectively, and the coefficient of variation was less than 7.2%. The recoveries forbutylparaben were 105, 95, and 107%, respectively, and the coefficient of variationwas less than 8.3%. The recoveries for caffeine were 101, 95 and 104%, respectively,and the coefficient of variation was less than 7.5%. Fifty-two commercial healthdrinks, tonic drinks and cold solutions were analyzed by the current method. Thenicotinamide content was found as: 20.3-241.7, 0-210.7 and 0-246.8mg/mL,respectively; the isobutylparaben content was found as: 0-54.1, 0-42.9 and 0-134.1mg/mL; the butylparaben content was found as: 0-106.8, 0-120.1 and 0-184.6mg/mL;and the caffeine content was found as: 0-433.2, 0-80.7 and 472.3-1742.9mg/mL.These results indicated that 6 out of 18 commercial health drinks, 2 out of 12commercial tonic drinks, and 2 out of 22 commercial cold formulas exceeded theTaiwan nicotinamide recommended daily nutrient allowances (RDNA, 14.4 ug) level.Furthermore, 25 out of 52 samples labeled