microtest® Test Kit Specifications

microtest Chlorine DPD

Colorimetric Test for


0.0 – 4 mg/L Cl2

Product Code658000
ContentsBuffer, 15 mL
Indicator, 2.5 g
Iodide Reagent, 15 mL
Cuvette, 4 mL (2x)
Colour chart
Instructions for Use
Analytical MethodDPD: At pH = 6.4, DPD (N,N-diethylphenylenediamine) is oxidised by free chlorine and forms a pink coloured compound. The intensity of the colour is related to the chlorine concentration. Chloroamines ("combined chlorine") can be determined by adding iodide, which is oxidised to iodine, which in turn also oxidises DPD.
Number of Tests80
InterferencesThis test is suitable for freshwater and seawater. Strongly alkaline or acidic samples have to be neutralised before testing. Bromine and iodine will be determined as chlorine. Other oxidants like chlorine dioxide, ozone and oxidised manganese compounds will give positive results.
Measuring RangeThe standard measuring range is 0 – 4 mg/L. The colour comparator has 6 colour fields: 0–0.2–0.5–1–2–4 mg/L. For higher chlorine concentrations, the sample has to be diluted. A 1:4 sample dilution can be carried out easily, thus extending the measuring range to 16 mg/L.
Shelf Life2 years
ApplicationsDetermination and monitoring of free and total chlorine levels in industrial water treatment (cooling towers), swimming pools, food processing, waste water.