This kit tests for QAC using the Direct Reading Titrator method. Range and sensitivity is 0-500 ppm/10 ppm Alkyl dimethyl benzyl ammonium chloride.
A masked bromphenol blue indicator is added to the sample and turns green. Sodium tetraphenylboron is added to complex the QAC and the color changes to red. This method is best suited to higher QAC concentrations.