purification of the sample with alumina adsorption alone , a method usually used for purification of catecholamines and dopa , was ineffective : epinephrine and norepinephrine , which are present in high concentrations , interfered with an accurate determination of dopa , and dopamine , which is retained strongly on the reverse-phase column , interfered with a rapid analysis .
C0007412
catecholamines
C0013023
dopa