 
            
        This is an Application Brief and does not contain a detailed Experimental section.
This application brief highlights the analysis of theophylline and related compounds using Symmetry Shield RP18 Columns.
The compounds analyzed in this study are:
 
            
        | Column: | Symmetry Shield RP18, 3.0 x 150 mm, 5 μm | 
| Part number: | 186000692 | 
| Mobile phase: | 5 mM potassium phosphate, pH 2.0/acetonitrile 95:5 | 
| Flow rate: | 0.6 mL/min | 
| Injection volume: | 5 μL injection of solution containing theobromine (0.22 mg/mL), theophylline (0.26 mg/mL), and 7-(2-hydroxyethyl) theophylline (0.13 mg/mL) | 
| Detection: | UV @ 270 nm | 
 
            
        WA31763.169, June 2003