RESUMEN
Methods for the determination of salicylazosulphapyridine (Salazopyrin(R)), sulphapyridine, N-acetylsulphapyridine, sulphapyridine-O-glucuronide and N-acetylsulphapyridine-O-glucuronide in serum and urine have been developed. In one method samples were diluted with methanol to precipitate proteins present and thereafter injected directly onto the liquid chromatographic column. The sulphapyridine-O-glucuronide could not be determined by this method. For the determination of all the main sulphapyridine metabolites the sulphapyridine aglycones were formed after treatment with beta-glucuronidase. These sulphapyridine compounds were then extracted with isobutylmethyl ketone at pH 5, and re-extracted to a phosphate buffer at pH 13 prior to injection. Separation and retention of all compounds was affected both by pH and concentration of methanol in the mobile phase. The proposed method made determinations down to 1 mug ml(-1) possible, which was found to be sufficient. Comparisons were made with spectrophotometric methods.