The DPD test is commonly used for the determination of which substance?

The DPD test, or Diethyl-p-Phenylene Diamine test, is primarily used for measuring the concentration of chlorine or bromine in water. This method is favored due to its sensitivity and accuracy, allowing for the determination of free available chlorine and total chlorine levels in various water samples, such as drinking water and swimming pools.

The DPD test works by reacting with chlorine or bromine in the presence of an appropriate buffer, producing a pink color proportional to the concentration of the disinfectant present. This colorimetric reaction is easy to read and can be quantified, which is essential for maintaining proper sanitation levels in water treatment.

Using this test is crucial for public health because adequate levels of chlorine or bromine ensure that water is free from harmful pathogens, making it safe for consumption and recreational use.