Isolation of drugs from blood serum by the Du Pont Prep I Automated Sample Processor and a C18 bonded phase adsorption column.

We describe a fast and efficient method for the isolation of drugs from blood serum by use of the DU PONT PREP I Automated Sample Processor and octadecyl bonded phase columns. Drugs are selectively adsorbed onto C18 bonded phase and eluted with methanol. The recovered residue is essentially free of sample matrix chromogens and shows very low background on thin layer chromatography. It is also suitable for analysis by gas liquid chromatography and high pressure liquid chromatography. Recovery of drugs added to serum is greater than 90 per cent for most drugs studied which include weakly acidic, neutral and alkaline drugs. The method offers tremendous savings to the user in time and dollars, since it is fully automated from the extraction step to the drying of the extract, and the columns are reusable at least 10 times. Up to 12 samples can be processed simultaneously in less than 60 minutes.