Chacabuco, Argentina
Chacabuco, Argentina

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Acosta G.,Area de Quimica Analitica | Acosta G.,Institute Quimica Of San Luis Cct San Luis | Silva R.,National University of San Luis | Gil R.A.,Area de Quimica Analitica | And 5 more authors.
Talanta | Year: 2013

Multiwalled carbon nanotubes are evaluated here as solid phase extraction (SPE) sorbent aiming to (±)-chlorpheniramine (CPA) enantioresolution with fluorimetric detection. β-cyclodextrin (CD) was added to the racemate and solutions with HCl and sodium dodecyl sulfate (SDS) in different proportions were assayed as eluents to achieve the separation between both enantiomers. The overall methodology involved a flow injection (FI) strategy enabling high sample throughput and low reagents consumption making it suitable for drug routine quality control. An adequate enantioresolution (2.08) with satisfactory responses for both (R)-CPA (peak area=285) and (S)-CPA (peak area=380) was achieved applying the proposed FI-SPE strategy under the optimized conditions [β-CD]=1.0 mmol L-1, [HCl]=1.0×10-2 mol L -1, [SDS]=4.0×10-4 mol L-1 and eluent flow rate=8.0 rpm. © 2012 Published by Elsevier B.V.


Escudero L.A.,Area de Quimica Analitica | Escudero L.A.,CONICET | Martinez L.D.,Area de Quimica Analitica | Martinez L.D.,CONICET | And 2 more authors.
Microchemical Journal | Year: 2010

An on-line zinc preconcentration and determination system implemented with inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. The zinc was precipitated and retained on a minicolumn filled with ethyl vinyl acetate (EVA) at pH 9.0, without using any complexing reagent. The zinc ions were eluted from the minicolumn with 10% (v/v) hydrochloric acid. Experimental conditions including pH and sample loading and eluting variables were evaluated and established. An enrichment factor (EF) of 44 was obtained for Zn2+ with a preconcentration time of 120 s. Under the optimal conditions, the value of the limit of detection (3σ) for the preconcentration of 10 mL of sample was 0.08 μg L- 1. The sampling frequency was about 24 h- 1. The precision for six replicate determinations (repeatability conditions) at 50 μg L- 1 Zn level was 3.94% relative deviation standard (RSD), calculated from the peak heights obtained. The methodology was successfully applied to the determination of zinc in tap water samples and in a certified VKI reference material QC Metal LL1 DHI (Water & Environment) Denmark. © 2009 Elsevier B.V. All rights reserved.


Multiwalled carbon nanotubes are evaluated here as solid phase extraction (SPE) sorbent aiming to ()-chlorpheniramine (CPA) enantioresolution with fluorimetric detection. -cyclodextrin (CD) was added to the racemate and solutions with HCl and sodium dodecyl sulfate (SDS) in different proportions were assayed as eluents to achieve the separation between both enantiomers. The overall methodology involved a flow injection (FI) strategy enabling high sample throughput and low reagents consumption making it suitable for drug routine quality control. An adequate enantioresolution (2.08) with satisfactory responses for both (R)-CPA (peak area=285) and (S)-CPA (peak area=380) was achieved applying the proposed FI-SPE strategy under the optimized conditions [-CD] = 1.0 mmol L(-1), [HCl] = 1.0 10(-2) mol L(-1), [SDS] = 4.0 10(-4) mol L(-1) and eluent flow rate = 8.0 rpm.

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