In this electrochemical technique the analyst applies a varying voltage to an electrode and records the current that flows through the reaction solution as it changes. The measurement cell carries three electrodes: the working electrode, where the compound of interest reacts; the auxiliary electrode, which completes the current path; and the reference electrode, which holds a steady potential so the working electrode’s voltage can be measured accurately. Sweeping the voltage produces current peaks that reveal which oxidisable or reducible substances are present and in what amount. Food laboratories apply it to antioxidants, vitamins, heavy metals, and pesticide residues, prizing its sensitivity, modest cost, and tolerance of messy sample matrices.