Caffeine, theophylline and theobromine determinations in serum, saliva and spinal fluid

A rapid method for simultaneous determination of caffeine and theophylline from the serum, saliva, or spinal fluid of neonates was developed. Fifty-microUter samples were extracted and analyzed by high-pressure liquid chromatography (HPLC) at a low accurately detectable limit of 0.1 mglUter. The sample preparation time was about 40 minutes. Instrumental analysis was performed in less than 10 minutes. Extraction efficiency from repeated analyses was determined to be 95 ± 10%. A precolumn was used to Increase the life of the analytical column. The EMIT-aad® method was compared to HPLC analysis and found to be less efficient.