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 2.5×10−10 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 6.0×10−6 mol l−1 ethamsylate, respectively. The modified electrode provides a linear response for ethamsylate in the concentration range from 4.0×10−7 to 1.0×10−3 mol l−1 by square wave adsorptive stripping voltammetry. The detection limit (three times the signal blank/slope) was 6.0×10−8 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.