Abstract
A method for the determination of ultra-trace aqueous ozone utilizing a membrane-separation process and a chemiluminescent detector is proposed. The microporous PTFE tube was used as separator to transfer aqueous ozone into a gas phase. Air bubbling was used to enhance the separation. Chemilumi nescent signals produced from the reaction of ozone with ethylene in air were linearly proportional to concentration of aqueous ozone from 8 ppb to 9.5 ppm. The relative standard deviation (n=4) was 3.5% at 0.2 ppm. The time it took from starting the sample flow until the signal to reach a stable level was 1.5 min. The interference from chromium(VI), manganese(VII), chlorine, bromine, phthalate, and sulfophthalate was completely eliminated.