SPE-HPLC DETERMINATION OF CATECHOLAMINES USING AN AFFINITY PRINCIPLE

Solid-phase extraction (SPE) with the affinity chromatography principl e was applied for high performance liquid chromatography (HPLC) determ ination of catecholamines in patients urine samples. Electrochemical a mperometric detection (ED) was used for all HPLC analyses and both ana lytical and microbore columns were tested for optimal chromatographic resolution of all analyzed catecholamines. Capacity ratio k' and detec tion limits were evaluated for all columns used.Precolumn affinity chr omatographic procedure of catecholamines with diphenylboronic acid (DP BA) in alkaline medium improved their retention on different commercia l SPE reversed-phase cartridges. After clean-up and preconcentration s tep the complex catecholamine-diphenylboronic acid was degraded by aci dic pH and eluted from SPE cartridge. After SPE affinity step catechol amines were analyzed by HPLC-ED. The optimal elution solutions was cho sen also as suitable SPE cartridges. Extraction recoveries of catechol amines were 89.6-93.3% with relative standard deviation RSD = 3.5-4.3% . Total analysis time was 30 min including 15 min for the preseparatio n procedure.