Simple in-line stopped flow photolysis of copper complexes in natural waters using a flow injection system

The development of an in-line digestion system based on simple UV lamp is reported. The effect of photolysis on the preconcentration of copper was investigated using an in-line Chelex-l00 ion-exchange column linked to an atomic absorption spectrometer. Three model ligands, glycine, NTA and EDTA, have been used to demonstrate the effect of the digestion system. In a stopped-flow mode, over 90% of the complexed copper was recovered in the presence of any of the three ligands. When the UV lamp was turned off, this changed to 84, 45 and 2% recovery for the glycine, NTA and EDTA complexed copper, respectively. The ability to analyse samples with the UV lamp on or off means that the device may be used to study the speciation of the copper.