Flow analysis method using chelating CIM monolithic disks for monitoring dissolved labile copper in environmental water samples

A low pressure flow analysis system incorporating a chelating monolithic disc for the selective retention and elution of Cu(II) from within environmental samples, is reported. Three monolithic discs were modified with either picolinic acid, dipicolinic acid, or dodecyliminodiacetic acid and the extraction and elution efficiency of Cu(II) on the three chelating phases compared. The dipicolinic acid disc showed the highest capacity and linear range for Cu(II) and was incorporated into a flow analysis system, using chemiluminescence detection based on the measurement of light emitted from the Cu(II) catalysed oxidation of 1,10-phenanthroline by hydrogen peroxide. The system gave a linear response (R-2 =0.998) over the concentration range 0-125 mu g L-1 in simulated seawater, with detection limits for Cu(II) of 5 mu g L-1 in a sample volume of just 220 mu L. Accuracy was determined using a standard reference material (SRM 1640) and the method applied to estuary and coastal seawater samples.