The proposed study aimed to create and validate a technique for detecting impurities in drug substances, specifically targeting low levels of ethylenediamine in pharmaceutical raw materials. The method involved the use of benzoyl chloride as a derivatizing agent, during pre-column derivatization processing, effectively boosting the sensitivity and precision of the method. Chromatographic conditions were optimized, including the use of 0.7g L-1 di-sodium hydrogen phosphate anhydrous and methanol, a specific XBridgeTM Shield RP-18 column, 10μL injection volume, and a flow rate of 0.8mL min-1 at 25°C. This method combined precolumn derivatization with RP-HPLC UV/PDA detection, proving highly sensitive and precise with favorable linearity (r ≥ 0.99) and precision (% RSD/CV < 5.0) upon validation. The developed method is noted for its simplicity, speed, cost-effectiveness, and suitability for regular analysis in QC labs, particularly for detecting impurities in drug candidates.