Simultaneous independent analysis of anions and cations using indirect photometric chromatography

Iskandarani, Ziad; Miller, Theodore E.

doi:10.1021/ac00285a021

Cited by 63 publications

(14 citation statements)

References 19 publications

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“…10 4 ) with a number of metal ions which spectra overlap extensively. The mutual interferences of metal ions can be diminished by application of suitable masking agents and various pH ranges [1][2][3][4][5][6][7][8] or multiple linear regression [9]. Derivative spectrophotometry offers an alternative approach to the enhancement of selectivity in the spectrophotometric analysis.…”

Section: Resultsmentioning

confidence: 99%

“…Of the different LC techniques, ion exchange has been the most frequently applied in the separation of metals. The usual detection technique is conductometry, although indirect photometric detection has also been described [2][3][4][5][6][7][8]. Several years ago, Sherman and Danielson [9] proposed spectrophotometric detection for the separation of alkaline and alkaline-earth-metals using cerium and copper as the mobile phases.…”

Section: Introductionmentioning

confidence: 99%

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Indirect flame atomic absorption detection for the liquid chromatographic separation of alkaline metals

Viñas

Campillo

López-Garcı́a³

et al. 1996

Analytical and Bioanalytical Chemistry

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Alkaline metals and ammonium ion are separated by cationic exchange liquid chromatography using a 60 microg ml(-1) aqueous copper solution as the mobile phase at 1.5 ml min(-1). Detection is carried out by measuring copper with an atomic absorption spectrometer directly interfaced to the chromatograph. A simple T-piece is used to compensate the difference between the nebulizer uptake rate and the chromatographic flow-rate with air. The method is applicable to the analysis of alkaline metals and ammonium in waters. Average recovery ( n = 16) was 100.3 +/- 4.0%.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Indirect flame atomic absorption detection for the liquid chromatographic separation of alkaline metals

Viñas

Campillo

López-Garcı́a³

et al. 1996

Analytical and Bioanalytical Chemistry

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“…From the size-exclusion chromatography data, the weight-average molecular weight of heparin employed was calculated to be 2.2 × 10 4 by using poly(ethyleneoxide) (PEO) as the standard, whereas the molecular weight of PEO completely excluded from the pore of the IC-Anion-SW packing is (5 -6) × 10 4 . From these estimations, it is presumed that heparin can enter the pore of the packing to some depth depending on the size and a portion of the inner part of the packing is remained unmodified.…”

Section: Modification With Heparinmentioning

confidence: 99%

“…Simultaneous separation of both anions and cations in a single chromatographic run has been challenged in various ways in ion chromatography [1][2][3][4][5][6][7][8][9][10][11]. Mixed bed of anion-exchange and cation-exchange materials [1,2] or the use of anionexchange and cation-exchange columns in tandem [3][4][5][6] can retain both anions and cations. Amphoteric stationary phases such as alumina [7] as well as zwitterionic stationary phases such as bile acids [8] also allow simultaneous separation of anions and cations on a single stationary phase.…”

Section: Introductionmentioning

confidence: 99%

Ion chromatography using anion exchangers modified with heparin

et al. 1998

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Abstract. Retention behavior of inorganic anions and cations on anion exchangers modified with heparin has been investigated. Retention of anions on the anion exchanger was remarkably reduced after the modification with heparin. The cations of the eluent affected the retention behavior of ions. The retention factor of anions decreased with decreasing eluent concentration when sodium sulfate and magnesium sulfate were used as the eluent, whereas it increased with decreasing eluent concentration when aluminium sulfate, copper sulfate and sulfuric acid were used as the eluent. When copper sulfate was used as the eluent, both anions and cations were retained on the modified stationary phase and simultaneous separation of both anions and cations were carried out. Cations as well as non-UV-absorbing anions were indirectly visualized by copper ions. Key words. Ion chromatography -heparin -simultaneous separation of anions and cations.Analusis, 1998, 26, 61-64 © EDP Sciences, Wiley-VCH * Correspondance and reprints. Received January 13, 1998; revised January 13, 1998; accepted January 16, 1998.Article available at http://analusis.edpsciences.org or http://dx.doi.org/10.1051/analusis:1998111 without any further treatment. Purified water was prepared in the laboratory by using a Mill-Q Plus system (Millipore, Molsheim, France). The eluents were prepared using the purified water. Modification with heparinThe IC Anion-SW column was first washed with water at a flow rate of 4.2 µL min -1 for 10 min and with 10 mM sodium sulfate at the same flow rate for 2 h. Aqueous solution of 1.0% heparin was then passed through the column at a flow rate of 4.2 µL min -1 for 2 h, followed by washing with water at the same flow rate for ca. 30 min. Results and discussion Modification with heparinThe expected structure of heparin is illustrated in figure 1. Since heparin has various anionic groups in its unit as in figure 1, it can be introduced into anion exchangers by electrostatic interaction. Since all of the anionic groups do not interact with the anion-exchange sites of the packing, a portion of anionic groups of heparin are remained free and they affect the retention of analyte ions. The repulsion of analyte anions from the modified surface may depend on the pH and the ionic strength of the eluent.The mass distribution of heparin employed in this work is illustrated in figure 2. From the size-exclusion chromatography data, the weight-average molecular weight of heparin employed was calculated to be 2.2 × 10 4 by using poly(ethyleneoxide) (PEO) as the standard, whereas the molecular weight of PEO completely excluded from the pore of the IC-Anion-SW packing is (5 -6) × 10 4 . From these estimations, it is presumed that heparin can enter the pore of the packing to some depth depending on the size and a portion of the inner part of the packing is remained unmodified. In other words, the modified packing possesses both negative charges due to free anionic groups of heparin and positive charges due to the original bare anion-exchange sites....

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“…Eluent species that have been evaluated for indirect W absorption detection of cations include copper(I1) (1)(2)(3)(4)(5)(6)(7), mixtures of copper(I1) and cobalt(I1) (4, 5), cerium(II1) (7), pyridine (2), aniline (for indirect refractive index detection) (8), benzylamine (9), and benzyltrimethylammonium bromide (2). Copper o-sulfobenzoate has been shown to be a suitable eluent for the simultaneous detection of anions and cations using indirect UV absorption (10). Cerium(II1) appears to be the most promising of the inorganic eluent ions, while the organic eluent ions studied to date have given only moderate sensitivity and poor chromatographic selectivity for alkali-metal solute ions.…”

Section: Introductionmentioning

confidence: 99%

Aromatic bases as eluent components for conductivity and indirect ultraviolet absorption detection of inorganic cations in nonsuppressed ion chromatography

Haddad¹,

Foley²

1989

Anal. Chem.

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1435sorption bands a t 276 and 338 nm have nearly identical absorptivities but are derived from optical transitions to two entirely different excited electronic states. Although the experimental error associated with the extremely weak fluorescence and phosphorescence emissions obtained by using 276 nm excitation are quite large, the near identity of the IplIf ratios shown in Figure 5b indicate that, as expected, rapid interconversion between the excited singlet states of pyrene prevails leaving the phosphorescence quantum yield insensitive to the fact that the excited singlet states resulting from excitation at 276 and 338 nm are different. LITERATURE CITEDKalyanasundram, K.; Grieser, F.; Thomas, J. K. Chem. fhys. Lett. Humphry-Baker, R.; Moroi. Y.; Gratzei, M. Chem. fhys. Lett. 1978, Turro, N. J.; Llu, K.-C.; Chow, M.-F.; Lee, P. fhotochem. fhotobiol. 1978, 27, 523-529. Almgren, M.; Grieser, F.; Thomas, J. K.A range of protonated aromatlc bases was Investigated as eluents for the nonsuppressed Ion chromatography of lnorganlc cations, uslng simultaneous dlrect conductlvlty and Indirect UV absorption detectlon. When a low-capaclty sty-rene4lvlnylbenzene cation-exchange column was used, m e thylpyrldlne Isomers, dlmethylpyridlne Isomers, benzylamlne, 2ghenylethylamlne, and 4-methylbenrylamlne proved suitable for the separatlon of alkall-metal cations and ammonium. Detectlon llmits were In the range 0.3-6.7 ppb for conductlvlty detection and 0.2-21.0 ppb for UV absorptlon detection. Alkaline-earth-metal catlons could be separated by using hlgher concentrations of the same eluent specles, glvlng detectlon limits of 9-917 and 1.3-1370 ppb for conductivity and UV absorption detection, respectlvely. Aromatlc base eluents were applied to the separatlon of calcium and magneslum In seawater and are potentlally sultable for the determlnatlon of aluminum.

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Simultaneous independent analysis of anions and cations using indirect photometric chromatography

Cited by 63 publications

References 19 publications

Indirect flame atomic absorption detection for the liquid chromatographic separation of alkaline metals

Indirect flame atomic absorption detection for the liquid chromatographic separation of alkaline metals

Ion chromatography using anion exchangers modified with heparin

Aromatic bases as eluent components for conductivity and indirect ultraviolet absorption detection of inorganic cations in nonsuppressed ion chromatography

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