Electrochemical oxidizing digestion using PbO2 electrode for total phosphorus determination in a water sample

Abstract

Total phosphorus is one of the key water quality parameters in environmental monitoring. To precisely determine the total phosphorus, water samples have to be pretreated to convert the various forms of phosphorus to orthophosphate. Conventionally, pretreatment is accomplished by heating, acidification, and oxidation in a digestion equipment, which is dangerous, time-consuming, and complicated. Herein, we propose a novel high-performance electrochemical oxidation protocol for phosphorus digestion based on a PbO₂ electrode. The electrode, which has a hydrophobic and stable surface, was prepared by electrochemical deposition on a titanium substrate and has high hydroxyl radical utilization when digesting total phosphorus. As a result, 90% of sodium glycerophosphate was digested within 30 minutes, and high digestion ratios of acephate, glyphosate, and inland water samples were obtained as well. In addition, this electrochemical digestion protocol does not required heating and acidification steps, which shortens the digestion time. Therefore, a rapid quantification of total phosphorus in the water sample was achieved.