INDIRECT GC DETERMINATION OF ETHEPHON IN DRINKING-WATER BY A COMBINATION OF REACTIVE HEADSPACE SAMPLING WITH ADSORPTIVE ENRICHMENT THERMAL-DESORPTION

An indirect GC method is described for the determination of Ethephon i n drinking water on the basis of the headspace analysis of the ethylen e formed from Ethephon. In order to reach the necessary detection limi t, the entire volume of the static headspace distribution is transferr ed into a cold injection system (CIS). There, the ethylene is adsorbed on Carbosieve SIII at 10-degrees-C and, subsequently, desorbed at 300 -degrees-C. The water vapour included in the headspace is completely e liminated through the splitting system. By means of this technique, a detection limit of 0.05 mug/l water was reached.