A microfluidic chip for sensing active chlorine and chloramines in swimming pools

A microfluidic platform consisting of four-layer glass chip was designed and fabricated for the photometric detection of active (hypochlorous acid) and bound (chloramine) chlorine in swimming pools. The microfluidic chip enables separate interrogation of the chemical reactions of active and bound chlorine with the same organic dye, methyl orange. The downstream-addition of a catalyzing agent allows the quantification of both chlorine residuals to be distinguished kinetically. Potential inaccuracies due to variable pH were eliminated by using the isosbestic point of methyl orange.