Methylxantines (1)
Methylxantines were analyzed using RSpak 
DS-613 (a column for reversed phase chromatography).

Sample : 0.02% each, 6micro-L
1. 
Xanthine
2. 
Theobromine
3. 
Theophyline
4. 
Caffeine
Column       : Shodex RSpak DS-613 (6.0mmID*150mm)
Eluent       : H2O/CH3CN=88/12
Flow rate    : 1.0mL/min
Detector     : UV(254nm)
Column temp. : 40deg-C