The construction and electrochemical response characteristics of poly(vinylchloride) (PVC) membrane selective electrodes for the determination of distigmine (Ds) are described. The sensing membrane comprised an ion-pair based on distigmine phosphomolybdate (Ds-PM), distigmine phosphotungstate (Ds-PT), distigmine silicomolybdate (Ds-SM), distigmine silicotungstate (Ds-ST), distigmine tetraphenylborate (Ds-TPB), and distigmine reineckate (Ds-Rein) in a plasticized PVC matrix with dioctylphthalate (DOP). The influence of membrane composition on the electrodes’ response was studied. | Using PVC ion-selective electrodes for the potentiometric flow injection analysis of distigmine in its pharmaceutical formulation and biological fluids