Authors: Vibha Gurnani Ajai K Singh B Venkataramani
Publish Date: 2003/08/06
Volume: 377, Issue: 6, Pages: 1079-1086
Abstract
New macromolecular chelators have been synthesized by loading 23dihydroxypyridine DHP on cellulose via linkers NHCH2CH2NHSO2C6H4N=N and SO2C6H4N=N and characterized by elemental analysis TGA IR and CPMAS 13C NMR spectra The cellulose with DHP anchored by the shorter linker had better sorption capacity between 697 and 4311 μmol g−1 for CoII NiII CuII ZnII CdII PbII and FeIII than the other 519–3781 μmol g−1 the former was therefore studied in detail as a solid extractant for these metal ions The optimum pH ranges for quantitative sorption recovery 976–998 on this matrix were 70–90 60–90 30–80 60–80 60–90 60–70 and 20–60 respectively Desorption was quantitative with 05 mol L−1 HCl and 05 mol L−1 HNO3 for Pb Simultaneous sorption at pH 70 of all metal ions other than FeIII was possible if their total concentration did not exceed the sorption capacity lowest value The recovery of seven metal ions from their mixture at pH 60 was nearly quantitative when the concentration level of each metal ion was 02 μg mL−1 The optimum flow rate of metal ion solutions for quantitative sorption of metal onto a column packed with DHPmodified cellulose was 2–7 mL min−1 whereas for desorption the optimum flow rate for the acid solution was 2–4 mL min−1 The time needed to reach 50 of the total loading capacity t 1/2 was 5 min for all the metal ions except Ni and Pb The limit of detection blank+3s was from 070 to 475 μg L−1 and the limit of quantification blank+10s was between 079 and 486 μg L−1 The tolerance limits for NaCl NaBr NaI NaNO3 Na2SO4 Na3PO4 humic acid EDTA CaII and MgII for sorption of all metal ions are reported The column packed with DHPanchored cellulose can be reused at least 20 times for enrichment of metal ions in water sample It has been used to enrich all the metal ions in pharmaceutical and water samples before their determination by flame AAS RSD for these determinations was between 11 and 69Authors thank Department of Atomic Energy India for granting the research project which supported this work AKS and VG thank the Council of Scientific and Industrial Research India also for financial support which has been partly used in this work
Keywords: