Evaluation of polychlorotrifluoroethylene as sorbent material for on-line solid phase extraction systems: Determination of copper and lead by flame atomic absorption spectrometry in water samples Original Research Article

Polychlorotrifluoroethylene (PCTFE) in the form of beads was applied, as packing material for flow injection on-line column preconcentration and separation systems coupled with flame atomic absorption spectrometry (FAAS). Its performance characteristics were evaluated for trace copper determination in environmental samples. The on-line formed complex of metal with diethyldithiophosphate (DDPA) was sorbed on the PCTFE surface. Isobutyl methyl ketone (IBMK) at a flow rate of 2.8 mL min−1 was used to elute the analyte complex directly into the nebulizer–burner system of spectrophotometer. The proposed sorbent material reveal, excellent chemical and mechanical resistance, fast adsorption kinetics permitting the use of high sample flow rates up to 15 mL min−1 without loss of retention efficiency. For copper determination, with 90 s preconcentration time the sample frequency was 30 h−1, the enhancement factor was 250, which could be further improved by increasing the loading (preconcentration) time. The detection limit (3s) was cL = 0.07 μg L−1, and the precision (R.S.D.) was 1.8%, at the 2.0 μg L−1 Cu(II) level. For lead determination, the detection limit was cL = 2.7 μg L−1, and the precision (R.S.D.) 2.2%, at the 40.0 μg L−1 Pb(II) level. The accuracy of the developed method was evaluated by analyzing certified reference materials and by recovery measurements on spiked natural water samples.