DETERMINATION OF SOME CARDIOVASCULAR DRUGS IN SERUM AND URINE BY CAPILLARY ISOTACHOPHORESIS

The separation and determination of amiloride, metoprolol, deacetylmet ipranolol, labetalol and furosemide in human serum and urine by capill ary isotachophoresis were investigated. Amiloride and beta-blockers we re separated by cationic isotachophoresis in the electrolyte system so dium morpholinoethanesulfonate buffer (pH 5.5) (c(L) = 10 mM)-glutamic acid. Furosemide was separated using the anionic electrolyte system h istidine hydrochloride buffer (pH 6.2) (c(L) = 10 mM)-morpholinopropan esulfonic acid. Endogenous and the possible exogenous compounds were a lmost totally removed from serum and urine by solid-phase extraction u sing a Separon SGX C-18 cartridge. The recovery of compounds varied fr om 98.2 to 103.2%. The linearity range for the compounds was 50-1000 n g/ml. The relative standard deviations varied from 0.1 to 5.6%. The ov erall limits of determination ranged from 32 to 46 ng/ml of urine and from 39 to 46 ng/ml of serum, depending of the type of drugs.