Fast HPLC analysis of adenine in human plasma using a new generation C ₂₈ column and different extraction methods

A fast, simple, inexpensive, selective, rugged and reproducible HPLC method based on the use of a new generation Sunniest RP-Aqua C₂₈ column is described for the analysis of adenine in plasma. Three methods for the extraction of adenine from human plasma i.e. by acetone, acetonitrile and solid phase cartridges are reported. The separation was performed via isocratic elution of adenine using water-acetonitrile (90:10, v/v) as mobile phase at a flow rate of 1.0 mL min^-1 and with detection at 260 nm. The values of retention factor in standard and plasma samples were 2.53 and 2.60, respectively. The method was validated and found to be linear at a concentration range of 5-1000 μg mL^-1. The limits of detection and quantification were lower than 0.3 and 0.91 μg mL^-1, respectively. The intra- and inter-day precisions (% RSD) were less than 9%. The accuracy values were between 99.8 and 107.4%. The extraction recoveries ranged from 95-80%.