SUPPORTED LIQUID MEMBRANES FOR SAMPLING AND SAMPLE PREPARATION OF PESTICIDES IN WATER

The use of supported liquid membranes for sampling and sample preparat ion of pesticides in water is described. A porous PTFE membrane is imp regnated with a water-immiscible organic solvent, giving the supported liquid membrane. The optimisation of the extraction processes; involv ing the pH of the donor and the acceptor, choice of membrane liquid an d donor flow-rate will be discussed. The technique has also been used for time integrating field sampling of acidic herbicides in natural wa ter samples. Examples of sample preparation of phenoxy acids, sulfonyl urea herbicides and triazines from natural water samples will be shown .