Reagentless dissolution and quantification of particulate analyte in a sample via membrane electrolysis

A method of detecting lead in tap water solution, the method comprising

• placing the tap water and potassium nitrate in an electrochemical cell, the electrochemical cell comprising:
• an anodic compartment configured to hold the tap water,
• a cathodic compartment, configured to hold the potassium nitrate, wherein the cathodic compartment is in fluid communication with the anodic compartment through an anion exchange membrane;
• a first electrode system comprising:
• a platinum mesh working electrode disposed in the anodic compartment,
• a first wire counter electrode disposed in the cathodic compartment;
• a second electrode system disposed in the anodic compartment, the second electrode system comprising:
• a glassy carbon working electrode,
• a second counter electrode, and
• a potentiostat communicatively coupled to the glassy carbon working electrode and configured to generate a current therein;
• acidifying the tap water in the anodic chamber comprising:
• generating a positive voltage in the platinum mesh electrode, wherein the positive voltage generates oxonium cations in the anodic compartment;
• maintaining the positive voltage on the platinum mesh electrode, thereby allowing nitrate to flow from the cathodic compartment into the anodic compartment through the anion exchange membrane;
• forming nitric acid in the anodic compartment, thereby lowering the pH of the tap water and dissolving the lead;
• applying a negative voltage to the glassy carbon electrode, thereby depositing the dissolved lead on the glassy carbon electrode;
• stripping the deposited lead from the glassy carbon electrode by applying a square wave potential pulse to the glassy carbon electrode, wherein the square wave potential pulse comprises alternating the potential between a base potential and a peak potential;
• and
• measuring a current response at the glassy carbon electrode as a function of the applied potential to generate an electrochemical voltammogram to determine the concentration of the lead in the tap water.