Rapid, sensitive and fully automated high-performance liquid chromatographic assay with fluorescence detection for sulmazole and metabolites.
Sulmazole (2-[(2-methoxy-4-methylsulfinyl)phenyl]-3H-imidazo [4,5-b] pyridine; AR-L 115 BS) and two metabolites (sulfide, sulfone) were quantified from directly injected body fluids (plasma, urine, bile) after high-performance liquid chromatographic separation. No internal standard is needed, which is particularly advantageous when fluorescence detection is established. After automated pre-column enrichment on Corasil C18 (37-50 microns), the parent compound and biotransformation products could be backflushed and chromatographed on ODS-Hypersil (5 microns) with a mixture of 0.075 mol/l phosphate buffer-acetonitrile (2:1), an elution rate of 2.0 ml/min and fluorimetric detection (lambda ex = 330 nm; lambda em = 370 nm). A hydroxylated metabolite of sulmazole which occurs preferentially in urine (and bile) can be quantified in the above-mentioned solvent system diluted 1:1 with water, but with different fluorescence characteristics (lambda ex = 345 nm; lambda em = 515 nm). The assay was linear in the range 8-1000 ng/ml. The lower limit of detection was about 8 ng/ml or 80 pg with coefficients of variation between 0.4 and 5.8% for sulmazole.
D000818:Animals; D001322:Autoanalysis; D001646:Bile / Q000032:analysis; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D007093:Imidazoles / Q000032:analysis* / Q000097:blood; D051381:Rats; D013050:Spectrometry, Fluorescence / Q000379:methods
D007093:Imidazoles; C040451:sulmazole sulfone; C040452:AR-L 113 BS; C029758:sulmazole