Determination of ethamsylate in the presence of catecholamines using 4-amino-2-mercaptopyrimidine self-assembled monolayer gold electrode

4-Amino-2-mercaptopyrimidine self-assembled monolayers (AMP/Au SAMs) have been fabricated on bare gold. The ethamsylate can adsorb onto the AMP/Au SAMs electrode surface to form a closely packed monolayer, whose surface concentration is 2.5 x 10(-10) mol cm(-2). The modified electrode was applied successfully to the determination of ethamsylate in the presence of dopamine, norepinephrine and epinephrine without prior separation, and could eliminate their interference at 40-, 70- and 110-fold concentration of 6.0 x 10(-6) Mol l(-1) ethamsylate, respectively. The modified electrode provides a linear response for ethamsylate in the concentration range from 4.0 x 10(-7) to 1.0 x 10(-3) mol l(-1) by square wave adsorptive stripping voltammetry. The detection limit (three times the signal blank/slope) was 6.0 x 10(-8) mol l(-1). The recovery experiment of standard addition in drug samples of ethamsylate showed the recoveries in the range of 98.7-103.1%. The modified electrode has been satisfactorily used for the determination of ethamsylate in pharmaceutical formulations. (C) 2004 Published by Elsevier B.V.