Separation and Preconcentration of Cr(VI) as Ion Associate Using Solid Phase Extraction

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Title:Separation and Preconcentration of Cr(VI) as Ion Associate Using Solid Phase Extraction
Creators:
Otruba, Vítězslav
Pivnička, Jan
Kanický, Viktor
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 65, 12, pp. 1865-1874
Uncontrolled Keywords:Solid phase extraction, Silica gel C18, Ion associates, Quaternary ammonium salts, Flame emission spectrometry, Surfactants, Sorption, Chromates, Chromium

Abstract

A method of separation and preconcentration of Cr(VI) was developed based on sorption on modified silica gel (C18) of an ion associate of Cr(VI) anion with a quaternary base. The study was performed with the following quaternary onium salts: [1-(ethoxycarbonyl)- pentadecyl]trimethylammonium bromide, 1-hexadecylpyridinium chloride, benzyl(dodecyl)- dimethylammonium bromide, butyl(triphenyl)phosphonium bromide and tetraphenylarsonium chloride. Benzyl(dodecyl)dimethylammonium bromide was found the optimum ion-pairing reagent. Sample containing Cr(III) and Cr(VI) in the presence of 0.005 mol/l of benzyl(dodecyl)dimethylammonium bromide was pumped with a peristaltic pump through the column containing the sorbent. The optimum pH range 4-5 was maintained with 0.05&nbsp;mol/l phosphate buffer. Elution was accomplished using 95 vol.% ethanol and the recovery of Cr(VI) was (96 ± 6)% in the concentration range 0.005-1 mg/l of Cr(VI); even in a tenfold excess of Cr(III) the recovery of Cr(VI) was 99.8% with the relative standard deviation of repeatability about 2.4% Cr in the eluate was determined by emission flame spectrometry (Cr I 425.435 nm) in an air-acetylene or N<sub>2</sub>O-acetylene flame with the limits of detection 10 or 2 ng/ml, respectively. Hence, with a typical preconcentration factor of 200, the limits of detection in natural aqueous samples were 50 and 10 pg/ml, respectively. Calibrations were linear at least up to 10 mg/l. <p>

Title:Separation and Preconcentration of Cr(VI) as Ion Associate Using Solid Phase Extraction
Creators:
Otruba, Vítězslav
Pivnička, Jan
Kanický, Viktor
Uncontrolled Keywords:Solid phase extraction, Silica gel C18, Ion associates, Quaternary ammonium salts, Flame emission spectrometry, Surfactants, Sorption, Chromates, Chromium
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:65
Number:12
Page Range:pp. 1865-1874
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20001865UNSPECIFIED
ID Code:1765
Item Type:Article
Deposited On:06 Feb 2009 17:12
Last Modified:06 Feb 2009 16:12

Citation

Otruba, Vítězslav; Pivnička, Jan; Kanický, Viktor (2000) Separation and Preconcentration of Cr(VI) as Ion Associate Using Solid Phase Extraction. Collection of Czechoslovak Chemical Communications, 65 (12). pp. 1865-1874. ISSN 0010-0765

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