4-phenylenediaminepropylsilica xerogel as a sorbent for copper determination in waters by slurry-sampling ETAAS

The synthesis of a new, hybrid mesoporous sorbent, 4- phenylenediaminepropylsilica ( 4- PhAP/ silica xerogel) obtained by the sol - gel process is described. This material was characterized by infrared spectroscopy ( IR), elemental analysis ( CHN), and nitrogen adsorption - desorption isotherms. Subsequently, this material was employed for the successful pre- concentration of copper in natural water reference materials. The copper characteristic mass was 15.0 +/- 0.2 pg. The detection limit for copper determination in natural waters employing the pre- concentration procedure was 0.2 mug l (-1). The average tube lifetime was 750 analytical firings when 20 mul of 1.5% m/ v copper sorbed on 4- PhAP/ silica xerogel slurry was delivered to a previously treated W - Rh treated platform of a transversely heated graphite atomizer ( TGA). The pre- concentration factor obtained with 4- PhAP/ silica xerogel as adsorbent for copper determination was 3.75 and the retention capacity of the sorbent was 0.52 mmol copper per gram of sorbent.