The determination of boron (¹¹B/¹⁰B) isotope ratios in natural and anthropogenic waters provides valuable insights for hydrogeological and environmental studies. This study reports an optimized version of a method originally developed by de la Vega et al. We conducted our study on various aquatic systems where samples were filtered and separated using ESI prepFAST and Amberlite IRA743 resin prior to analysis. Boron isotope ratios were measured using MC ICP MS (Neptune Plus, Thermo Scientific) with a sodium fluoride wash solution employed between analysis to minimize boron memory effects, and NIST SRM 951a and BAM 120-122 were used as reference materials. Our method resulted in a LOD of 1.4 ng/mL with the average recovery rate below 100%. In our recent approach, the recovery rates are being optimized by increasing the pH, which improves the binding efficiency of the resin, leading to higher recovery rates.