ONLINE PRECONCENTRATION OF TRACE COPPER FOR FLAME ATOMIC-ABSORPTION SPECTROMETRY USING A SPHERICAL CELLULOSE SORBENT WITH CHEMICALLY BOUND QUINOLIN-8-OL

Preconcentration was effected using a 50 mm × 2 mm i.d. minicolumn packed with a spherical cellulose sorbent with chemically bound quinolin-8-ol function groups (Ostorb Oxin). The column was connected to the nebulizer of the atomic absorption spectrometer and the sample solution and eluent (2 M hydrochloric acid) were sucked through it at a flow-rate of 2-3 ml min-1 by utilizing the negative pressure of the nebulizer. The experimental design was tested with the determination of traces of copper. Peak-area and peak-height measurements were compared. Owing to the simple calibration, the former method was used for quantification. The dynamic range was from 0.3 ng ml-1 (detection limit) to 5 μg ml-1 (breakthrough). The reproducibility in the concentration range 25 ng ml-1-5 μg ml-1 was better than 5%. Water-soluble inorganic salts, ammonia and sodium hydroxide were analysed. The accuracy of the results was checked by anodic-stripping voltammetry and by electrothermal AAS. © 1990.