摘要
A novel adsorbent was developed by coating yttrium hydroxide precipitate layer on cellulose fibre. This material takes up ca. 98% of 5 μg·L 1 As（Ⅲ） and As（V） at low pH （pH〈7）, while a favorable selectivity for As（V） was achieved within pH 11--12. In practice, a mini-column packed with Y（OH）3 precipitate layer coated cellulose fibre particles was incorporated into a sequential injection system for selective uptake of arsenate at pH 11.5. The retained arsenate was afterwards recovered with 50μL of 0.8 mol.L l NaOH solution as eluent, followed by hydride generation in a reaction medium of 2.0 mol·L-1 HCl and 1.0% NaBH4 solution （W/V, in 0.5% NaOH） after pre-reduction of arsenate to arsenite by KI-ascorbic acid （5%, W/V）, with detection by atomic fluorescence spec- trometry. Total inorganic arsenic was quantitatively taken up at pH 6.0 by following the same procedure and arsenic speciation was performed by difference. With a sample volume of 1.0 mL, an enrichment factor of 16.4 was derived with a detection limit of 17 ng.L-1 within a linear range of 0.05--2.0μg.L ]. A relative standard deviation （RSD） of 2.6% （0.5 μg·L-1, n= 11） was achieved. The procedure was validated by analyzing arsenic in a certified refer- ence material GBW 09101 （human hair）, and speciation process requires no organic solvents, thus Y（OH）3 coated of inorganic arsenic in natural water samples. The entire cellulose fibre provides a green adsorbent.
A novel adsorbent was developed by coating yttrium hydroxide precipitate layer on cellulose fibre. This material takes up ca. 98% of 5 μg·L 1 As（Ⅲ） and As（V） at low pH （pH〈7）, while a favorable selectivity for As（V） was achieved within pH 11--12. In practice, a mini-column packed with Y（OH）3 precipitate layer coated cellulose fibre particles was incorporated into a sequential injection system for selective uptake of arsenate at pH 11.5. The retained arsenate was afterwards recovered with 50μL of 0.8 mol.L l NaOH solution as eluent, followed by hydride generation in a reaction medium of 2.0 mol·L-1 HCl and 1.0% NaBH4 solution （W/V, in 0.5% NaOH） after pre-reduction of arsenate to arsenite by KI-ascorbic acid （5%, W/V）, with detection by atomic fluorescence spec- trometry. Total inorganic arsenic was quantitatively taken up at pH 6.0 by following the same procedure and arsenic speciation was performed by difference. With a sample volume of 1.0 mL, an enrichment factor of 16.4 was derived with a detection limit of 17 ng.L-1 within a linear range of 0.05--2.0μg.L ]. A relative standard deviation （RSD） of 2.6% （0.5 μg·L-1, n= 11） was achieved. The procedure was validated by analyzing arsenic in a certified refer- ence material GBW 09101 （human hair）, and speciation process requires no organic solvents, thus Y（OH）3 coated of inorganic arsenic in natural water samples. The entire cellulose fibre provides a green adsorbent.
