title: On-line Determination of Zinc in Water and Biological Samples after Its Preconcentration onto Zincon Anchored Polyurethane Foam.
abstract: A fast and sensitive on-line procedure for the determination of zinc in water and biological samples was developed. Zinc was preconcentrated in a mini-column packed with polyurethane foam (PUF) chemically modified with zincon via -N=N- bonding. The optimal conditions for preconcentration were pH 8.5 and sample flow rate of 4.0 mL min(-1). Quantitative desorption of Zn(II) was obtained by 0.1 mol L(-1) hydrochloric acid and subsequent spectrophotmetric determination using 4-(2-pyridylazo)-resorcinol at 498 nm. The obtained detection limit was found to be 3.0 ng mL(-1), precision (RSD) was 4.8 and 6.7% at 20 and 110 ng mL(-1), respectively, for 60 s preconcentration time and enrichment factor was 31. The linearity range was from 10 to 120 ng mL(-1) and maximum sample throughput was 20 h(-1). Finally, the method was successfully applied to the determination of zinc in tap water, Nile River water and human urine samples with RSD in the range of 1.1 - 8.3%.
authors.affiliation: Chemistry Department, Faculty of Science, Fayoum University, 2) Collage of Science and Humanities-Al-Quwaiyah, Shaqra University-KSA.
authors.forename: Sami M Abdel
authors.initials: SM
authors.lastname: Azeem
authors.forename: Hassan A
authors.initials: HA
authors.lastname: Hanafi
authors.forename: M F
authors.initials: MF
authors.lastname: El-Shahat
mesh_terms: D060766:Drinking Water / Q000737:chemistry*; D006801:Humans; D011140:Polyurethanes / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D015032:Zinc / Q000032:analysis* / Q000652:urine*
chemical_list: D060766:Drinking Water; D011140:Polyurethanes; C028279:polyurethane foam; D015032:Zinc