FLOW-ANALYSIS FOR TRACE AMOUNTS OF COPPER BY ION-EXCHANGER PHASE ABSORPTIOMETRY WITH 4,7-DIPHENYL-2,9-DIMETHYL-1,10-PHENANTHROLINE DISULFONATE AND ITS APPLICATION TO THE STUDY OF KARST GROUNDWATER STORM RUNOFF

Ion-exchanger phase absorptiometry was applied to flow analysis for trace amounts of copper in water. The increase in the absorbance of the coloured complex with 4,7-diphenyl-2,9-dimethyl-1,10-phenanthroline disulphonate, which was concentrated on-line on to an ion exchanger packed in a flow-through cell, could be measured continuously with a spectrophotometer at 484 nm. The detection limit was 0.08 ng cm-3 with 8.3 cm3 of sample solution. The proposed method permitted a highly sensitive, selective determination of copper in karst groundwater samples without any preconcentration. By measuring the copper concentration response in water after a storm, the infiltration rate of rain water from the soil zone to the underground river of a karst groundwater system could be evaluated to be about 10-20 m day-1.