Polarographic Assay of Hydrogen Peroxide Accumulation in Microbial Cultures

A method is described for determining low concentrations of hydrogen peroxide by using a polarographic oxygen electrode to measure the oxygen released into solution on addition of catalase. A sample can be assayed directly without prior manipulation in 3 min. The method is capable of assaying hydrogen peroxide concentrations as low as 7 μM. The method has proved extremely useful for the assay of hydrogen peroxide secreted into milk by lactic acid bacteria.