This research aims to study the effect of certain analytical conditions to determine the arsenic in in mixed media (water _ alcohol ) where the user either alcohol ( methanol, ethanol , propanol using a Potentiometric, and then selected as conditions optimal certified for this determine. The effect of each of the (PH value, type, concentration electrolyte, effect of crippling electrolytes) to determine the arsenic in mixed media ( 50:50 water _ alcohol ) and calibration using a standard solution of iodine.In addition to that, there are technical conditions must be tuned to determine the actual value of the end point calibration and data processing of standard solution (initial velocity and deceleration near the end point calibration). The study showed that the PH value appropriate for calibration of arsenic with iodine (pH=8), also found that the response process of arsenic on the electrode platinum has been excellent when using NaHCO3 as electrolyte with concentration of 1 M, which has been successfully used to quantify arsenic As+3, where the value reached detection limit of arsenic to (1×10-5M) in media (50:50water _ methanol ) , but when you use a media ( 50:50 water _ ethanol ) arrived to the limit of detection (1×10-3 M ), As for propanol arrived to the limit of detection (1×10-2 M). Was calculated as the standard deviation and standard deviation percentile confidence limit in addition to the feedback that indicates the efficiency of the method of determining the concentration of arsenic and detection limit for each medium.