Disposable screen-printed ring disk carbon electrode coupled with wall-jet electrogenerated iodine for flow injection analysis of arsenic(III)

We report here a wall-jet electrogenerated iodine approach for sensitive detection of arsenite (AsIII) by using a disposable screen-printed ring disk carbon electrode. Iodide (I−) is first oxidized to iodine (I2) at the disk electrode; the electrogenerated I2 can be effectively reduced back to I− in the presence of AsIII. The inhibited reduction current of I2 to I− can thus be monitored at the ring electrode and used for AsIII analysis. Various factors influencing the flow injection analysis (FIA) of AsIII were thoroughly investigated in this study. Under the optimized conditions, a linear calibration plot up to 10 μM with a detection limit (S/N = 3) of 70 nM was obtained by using 50 μM KI as the mobile phase in FIA. Practical utility of the proposed method was demonstrated to detect AsIII in “Blackfoot” disease endemic village groundwater from southwestern coast area of Taiwan (Pei-Men).