PURPOSE: To secure an accurate and easy determination for the analysis of the catechol amine via the liquid chromatography by carrying out the separation and concentration for the catechol amine contained in the sample material by means of the concentrated column and then introducing the catechol amine to the analysis column.

CONSTITUTION: The concentrated column is put before the analysis column. The solution (solution to be tested) containing the catechol amine is introduced to the concentrated column into which the filler (such as glycol gel containing boric acid) which can adsorb the catechol amine is filled and by means of the concentrating eluate (buffer solution of salt conentration 0.01W3M/l and pH8W10). Thus the catechol amine is adsorbed into the column for concentration. Then the concentrated column is connected via operation of the cock or the like before the analysis column into which th filler (such as the silica gel combining the octyl, ether groups, etc.) capable of separating the catechol amine is filled. And then the analyzing eluate (buffer solution of salt concentration 0.01W3M/l and pH2W4) is circulated to give analysis to the catechol amine.