Separation and preconcentration of trace manganese from various samples with Amberlyst 36 column and determination by flame atomic absorption spectrometry.
ABSTRACT This work assesses the potential of a new adsorptive material, Amberlyst 36, for the separation and preconcentration of trace manganese(II) from various media. It is based on the sorption of manganese(II) ions onto a column filled with Amberlyst 36 cation exchange resin, followed by the elution with 5mL of 3mol/L nitric acid and determination by flame atomic absorption spectrometry (FAAS) without interference of the matrix. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of sample solution, volume and concentration of eluent, and matrix effects for preconcentration were investigated. Good relative standard deviation (3%) and high recovery (>95%) at 100mug/L and high enrichment factor (200) and low analytical detection limit (0.245mug/L) were obtained. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 88mg/g of manganese on the resin. The method was applied for the manganese determination by FAAS in tap water, commercial natural drinking water, commercial treated drinking water and commercial tea bag sample. The accuracy of the method is confirmed by analyzing the certified reference material (tea leaves GBW 07605). The results demonstrated good agreement with the certified values.
- [show abstract] [hide abstract]
ABSTRACT: Mixture of pyridine-2,6-dimethanol (PDM) and thiocyanate (SCN−) (1:1, mole ratio) immobilized on silica served as a very efficient sorbent for selective retention of Co(II) from other associated metal ions at trace level. The maximum sorption capacity for Co(II) was found to be 0.203 mmol g−1 at pH 9.0. Sorbed Co(II) was completely eluted by 3.5 mL of 3 mol L−1 HCl and measured using flame atomic absorption spectrometer (FAAS). The structure of the extracted Co(II) complex was confirmed by single crystal Xray structure and Fourier transform infrared (FTIR) spectroscopy. Thermo gravimetric analysis (TGA) of the chelated Co(II) complex revealed its stability at the optimum extraction temperature (55 ◦C). The method was reproducible with a relative standard deviation (RSD) of 0.6% (N = 10) with three sigma detection limit (N = 10) of 0.6 �g g−1. A pre-concentration factor, 94 was achieved. Interferences from Mn2+ and Cu2+ ions were eliminated by prior oxidation of Mn2+ by KIO4 to MnO4 − and masking of Cu2+ with NH4SCN, respectively. A plausible mechanism for the selective extraction of Co(II) was attributed to the formation of a first order water insoluble inner–metallic complex as confirmed by the single crystal X-ray structure analysis. The developed method has been tested for trace level separation and estimation of cobalt in some certified reference materials. Analyses of some biological and environmental samples were performed.Chemical Engineering Journal 01/2011; 174:58-67. · 3.47 Impact Factor
- CLEAN - Soil Air Water 07/2010; 38(7):657 - 662. · 2.05 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: A speciation procedure based on the coprecipitation of manganese(II) with zirconium(IV) hydroxide has been developed for the investigation of levels of manganese species. The determination of manganese levels was performed by flame atomic absorption spectrometry (FAAS). Total manganese was determined after the reduction of Mn(VII) to Mn(II) by ascorbic acid. The analytical parameters including pH, amount of zirconium(IV), sample volume, etc., were investigated for the quantitative recoveries of manganese(II). The effects of matrix ions were also examined. The recoveries for manganese(II) were in the range of 95-98%. Preconcentration factor was calculated as 50. The detection limit for the analyte ions based on 3 sigma (n=21) was 0.75 microg L(-1) for Mn(II). The relative standard deviation was found to be lower than 7%. The validation of the presented procedure was performed by analysis of certified reference material having different matrices, NIST SRM 1515 (Apple Leaves) and NIST SRM 1568a (Rice Flour). The procedure was successfully applied to natural waters and food samples.Journal of hazardous materials 09/2009; 173(1-3):773-7. · 4.14 Impact Factor