High-performance liquid chromatography of tetracyclines.

The possibilities of two non-ionogenic resins (XAD-2 and PRP-1) in the chromatography of tetracyclines and their degradation products are described. It appears that, in contrast to silica-based materials, this type of column material produces linear calibration curves, even in the low nanogram range. Two different methods of sample pretreatment in bioanalysis of tetracyclines and their degradation products are compared with respect to selectivity towards the matrix background and recovery.