On-line Determination of Zinc in Water and Biological Samples after Its Preconcentration onto Zincon Anchored Polyurethane Foam

• Published in: Analytical Sciences Vol. 31; no. 5; pp. 391 - 397
• Main Authors: AZEEM, Sami M. Abdel, HANAFI, Hassan A., EL-SHAHAT, M. F.
• Format: Journal Article
• Language: English
• Published: Singapore The Japan Society for Analytical Chemistry 2015; Springer Nature Singapore; Japan Science and Technology Agency
• Subjects: Analytical Chemistry; Biological; Bonding; Chemistry; Drinking Water - chemistry; Humans; Hydrochloric acid; Mathematical analysis; On-line systems; Polyurethane foam; Polyurethanes - chemistry; preconcentration; Rivers - chemistry; spectrophotometry; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Urine; Zinc; Zinc - analysis; Zinc - urine; Zincon; polyurethane foam; spectrophotometry; preconcentration; Zincon
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.31.391

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%.