PORTABLE TRAP-SENSOR SYSTEM FOR MONITORING LOW-LEVELS OF ETHYLENE

A portable device for measuring trace amounts of ethylene is described , Ethylene was trapped on a silver catalyst, which was then flash heat ed, releasing a plug of ethylene into a flowing gas stream, The ethyle ne was detected using an amperometric sensor with a gold-Nafion sensin g electrode, For a trap time of 10 min, a detection limit of 1 ppb of ethylene was:achieved. This compares with 40 ppb obtained using the se nsor without pretrapping. In addition to the improvement in sensitivit y, the,trapping procedure also allowed improved selectivity, making th e device suitable for applications where very low levels of ethylene n eed to be measured and interferents may be present.