Preconcentration of trace elements by using 1-(2-Pyridylazo)-2-naphthol functionalized Amberlite XAD-1180 resin and their determination by FAAS

Abstract

Neste estudo foi sintetizada a resina Amberlite XAD funcionalizada por 1-(2-piridilazo)-2-naftol (PAN) e a resina resultante foi usada na pré-concentração dos íons Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Cd(II) e Pb(II) presentes em baixas concentrações em diferentes amostras. Para isso, o copolímero foi nitrado, reduzido à correspondente amina, convertido ao sal diazonato com nitrito e em reação com PAN produziu a resina complexante XAD-1180-PAN. Para o método descrito, parâmetros analíticos para recuperação dos elementos traço foram avaliados tais como, pH, volume da amostra, quantidade de resina, vazão de retenção e remoção, volume e tipo de eluente. Os metais retidos na resina XAD-1180-PAN foram eluídos com HNO 3 2 mol L -1 . A influência dos íons presentes na matriz, ou seja, Na(I), K(I), Ca(II) e Mg(II), sobre a recuperação dos elementos traço também foi avaliada, quando presentes isoladamente ou em conjunto. A repetibilidade do método foi avaliada nas condições experimentais ótimas estabelecidas. Os valores de recuperação, para todos os elementos, exceto o Cr(III), foram ≥92% e os desvios padrão relativos ≤8.5%. In this study, Amberlite XAD-1180 resin functionalized by 1-(2-pyridylazo)-2-naphthol (PAN) was synthesized and the resulting resin was used for preconcentration of Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Cd(II) and Pb(II) elements present at trace levels in different matrices. For this purpose, the copolymer was nitrated, reduced to the corresponding amine, converted to the diazonium salt with nitrite and reacted with PAN to produce the XAD-1180-PAN chelating resin. For the described method, the effect of some analytical parameters, such as pH, sample volume, resin amount, flow rates of uptake and stripping, volume and type of eluent, on the recovery of the trace elements was investigated. The metals retained on the XAD-1180-PAN resin were eluted by 2 mol L -1 HNO 3 . The influence of matrix ions, i.e., Na(I), K(I), Ca(II) and Mg(II), on the recovery of trace elements was also examined by using the developed method when they occurred both individually and together. The repeatability of the method at the optimum conditions determined experimentally was investigated. The recovery values for all the elements, except for Cr(III), were found to be ≥92% and the relative standard deviation was ≤8.5%. The 3s/b detection limits for Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Cd(II) and Pb(II) were found to be 4.1, 0.13, 2.7, 1.2, 0.19, 0.06 and 0.13 μg L -1 , respectively. The developed method was utilized for preconcentration and determination of Mn(II), Fe(III), Ni(II), Cu(II), Cd(II) and Pb(II) in tap water, rain water, and stream water, and of Ni(II), Cd(II) and Pb(II) in a certified reference material (RM 8704 Buffalo river sediment) by flame atomic absorption spectrometry (FAAS).

Application of 4-(2-pyridylazo)resorcinol for flotation-spectrophotometric determination of iron

“…Complexes of Fe II or Fe III and PAR have been investigated and by many authors [2][3][4][5][6][7][8][9][10][11]. Sometimes, the authors' opinions on various issues concerning the composition, iron oxidation state, or solubility of the complexes in different solvents are contradictory.…”

Preconcentration and Determination of Fe(III) from Water and Food Samples by Newly Synthesized Chelating Reagent Impregnated Amberlite XAD-16 Resin

“…Many reagents are suggested for determination of iron(III) by solid-phase extraction: gallic acid, 13 4-(2-pyridylazo)-resorcinol, 7 chromotropicacid, 15,16 N-benzoyl-N-phenyl hydroxylamine, 4 2-mercaptobenzimidazol, 17 5-sulfosalicylic acid, 18 2,3-dihydroxy benzoic acid, 19 purpurogallin, 20 acetylsalicylic acid, 21 and curcumin. 1 In this work, a new reagent, 5-hydroxy-4-ethyl-5,6-di-pyridin-2-yl-4,5-dihydro-2H-[1,2,4]triazine-3-thione (HL) was synthesized and it was characterized by using FT-IR spectroscopy and elemental analysis.…”

“…Several studies have been reported for the XAD series resins which are impregnated with various reagents. [7][8][9][10][11][12] The large surface area of Amberlite XAD-16 resin (800 m 2 g -1…”

Simultaneous Determination of Rare Earth Elements by ICP OES After On-Line Enrichment Using Multi-Walled Carbon Nanotubes Coated Cellulose Acetate Membrane

“…It has been also used as a chelating agent for the SPE separation and preconcentration of trace metals in various media. 20,21 In previous studies, PAN has been successfully employed for solid phase extraction of REEs with different adsorbents, such as octadecyl functional groups bonded on silica gel and ion-pair microparticles. 4,22 This work describes a simple, efficient and relatively inexpensive on-line method for the determination of some rare-earth elements (Y, La, Ce, Nd, Sm, Gd and Dy) in aqueous samples using ICP OES after preconcentration using carbon nanotube coated cellulose acetate membrane.…”