University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Shayessteh Dadfarnia

Abbrev:
Dadfarnia, S.
Other Names:
Address:
Department of Chemistry, Yazd University, Yazd, Iran
Phone:
+98-351-8212795
Fax:
+98-351-7250110

Citations 5

"Trace Enrichment And Determination Of Silver By Immobilized DDTC Microcolumn And Flow Injection Atomic Absorption Spectrometry"
Talanta 2004 Volume 64, Issue 3 Pages 682-687
S. Dadfarnia, A. M. Haji Shabani and M. Gohari

Abstract: Flow injection (FI) system incorporating a microcolumn of immobilized diethyldithiocarbamate (DDTC) on surfactant-coated alumina was combined with atomic absorption spectrometry for on-line trace enrichment and determination of silver in different matrices. Silver was deposited on the microcolumn by processing a standard or solution of analyte at pH 3-4 on the column. Injection of 250 µl of ethanol then served to elute the retained species to atomic absorption spectrometry (AAS). A sample volume of 20 mL resulted in a pre-concentration factor of 125, and precision at the 20 µg L-1 was 4% (RSD). The procedure was applied to tap water, well water, rain water, sea water, radiology film, and lead concentrate samples. The accuracy was assessed through recovery experiments, independent analysis by furnace-AAS, and analysis of certified reference material.

"Online Trace Enrichment And Determination Of Cobalt Ion As An Anionic Complex By Flow Injection Atomic Absorption Spectrometry"
Microchem. J. 1999 Volume 63, Issue 2 Pages 226-234
Shayessteh Dadfarnia and Mohammad Hossein Jafarzadeh

Abstract: A flow injection system incorporating a microcolumn of activated alumina was combined with atomic absorption spectrometry for online trace enrichment and determination of cobalt in waters and vitamin B-12. Deposition of cobalt as its cyano complex was effected with the use of an acidic alumina microcolumn, and injection of ammonia solution (500 µl, 2 M) served to elute species retained on the atomic absorption spectrometer. A sample volume of 15 mL resulted in a pre-concentration factor of 120, and precision at the 500 and 50 µg L-1 levels was±3.1 and±3.3% (RSD), respectively. The procedure was applied to mineral water, spring water, river water, and vitamin B-12 and accuracy was assessed through a recovery experiment.
Activated alumina Column Preconcentration

"Immobilized Stearic Acid As A New Sorbent For On-line Preconcentration And Determination Of Lead By Flow Injection Flame Atomic Absorption Spectrometry"
J. Braz. Chem. Soc. 2006 Volume 17, Issue 3 Pages 548-554
Shayessteh Dadfarnia*; Ali Mohammed Haji Shabani; Zahra Dehghani

Abstract: The present study examines the possibility of immobilization of stearic acid on microcrystalline naphthalene for preparation of microcolumn and evaluation of its potential for adsorption and pre-concentration of trace amounts of metal ions. It was found that this sorbent has high affinity for lead. Consequently, a rapid on-line pre-concentration technique for the determination of lead by Flow Injection Flame Atomic Absorption Spectrometry had been devised. Preconcentration was based on accumulation of analyte on immobilized stearic acid microcolumn and subsequent elution by injection of a small volume of nitric acid (250 µL of 1 mol L-1). A sample volume of 20 mL resulted in a pre-concentration factor of 84, and relative standard deviations for solutions containing 40 and 200 ?g L-1 were 5.1 and 1.2%, respectively. The procedure was applied to tap water, river water, sea water, apple juice, beet leaf, urine, and certified stainless steel. The accuracy was proved by performing recovery experiments, Graphite Furnace Atomic Absorption Spectrometry measurements, and analysis of a stainless steel certified reference material. ©2006 Sociedade Brasileira de Qui?mica.

"Immobilized 1,5-diphenylcarbazone As A Complexing Agent For On-line Trace Enrichment And Determination Of Copper By Flow Injection-atomic Absorption Spectroscopy"
J. Anal. At. Spectrom. 2002 Volume 17, Issue 10 Pages 1434-1438
Shayessteh Dadfarnia, Ali Mohammed Salmanzadeh and Ali Mohammed Haji Shabani

Abstract: A rapid on- line pre-concentration technique for the determination of copper in different samples by FI- AAS has been devised. Preconcentration is based on the deposition of analyte on a micro- column of 1,5- diphenylcarbazone immobilized on surfactant coated alumina and subsequent elution by injection of a small volume of hydrobromic acid (500 µL of 0.75 mol L-1 acid). A sample volume of 30 mL resulted in a pre-concentration factor of 100, and precisions at the 100 and 10 µg L-1 levels were 3.2 and 3.5% RSD, respectively. The procedure was applied to spring water, well water, sea- water, stainless steel and a multivitamin tablet and the accuracy was assessed through recovery experiments, independent analysis by furnace- AAS, and the analysis of a certified reference material.
Dithizone

"Immobilized Salen (N,N-bis (salicylidene) Ethylenediamine) As A Complexing Agent For On-line Sorbent Extraction/preconcentration And Flow Injection-flame Atomic Absorption Spectrometry"
Anal. Chim. Acta 2005 Volume 539, Issue 1-2 Pages 69-75
hayessteh DadfarniaCorresponding Author Contact Information, E-mail The Corresponding Author, Ali Mohammed Haji Shabani, Fatema Tamaddon and Maryam Rezaei

Abstract: The microcolumn of salen I (N,N?-bis (salicylidene) ethylenediamine) immobilized on surfactant-coated alumina has been used for on-line pre-concentration of copper and lead with a flow injection-flame atomic absorption spectrometry (FI-AAS). Various parameters affecting the deposition/elution processes in the FI-AAS system was optimized. Deposition of analytes was affected at pH of ?9, and injection of nitric acid (250 µL 2 mol l-1) served to elute retained species to AAS. A good relative standard deviation of 4.5 and 3.8% at 30 ?g l-1(n = 7), high enrichment factors of 100 and 75, and detection limits of 0.3, 2.6 ?g l -1 (3S) for Cu(II) and Pb(II) were obtained, respectively. The method was applied to water samples, multivitamin tablet and standard reference alloys (C12E41 and C12X3500) and accuracy was assessed through recovery experiment and independent analysis by furnace AAS, or comparing the results with the accepted values. © 2005 Elsevier B.V. All rights reserved.