On-line preconcentration and chiral separation of propiconazole by cyclodextrin-modified micellar electrokinetic chromatography

Ibrahim, Wan Aini Wan; Hermawan, Dadan; Sanagi, Mohd Marsin

doi:10.1016/j.chroma.2007.09.003

Cited by 46 publications

(41 citation statements)

References 24 publications

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“…At acidic pH separation, the basicity of the triazole fungicides was too weak (weak protonation of the triazole rings), thus the use of micelle was necessary. This is supported by our previous study where the use of 10 and 25 mM SDS was not able to separate the stereoisomers of propiconazole, a triazole fungicide [39]. At acidic pH, sweeping CD-MEKC separation was achieved with 40 mM SDS and at pH 7, CD-MEKC separation was achieved with 50 mM SDS and above.…”

Section: Resultssupporting

confidence: 72%

“…A 25 mM phosphate buffer solution at pH 3 was used based on the optimized condition of a previous study [39], which resulted in the separation of two pairs of propiconazole enantiomers. Propiconazole is one of the triazole fungicides Electrophoresis 2009,30,[1976][1977][1978][1979][1980][1981][1982] and has hydrophobicity close to the selected triazole fungicide used in this study.…”

Section: Resultsmentioning

confidence: 99%

“…Propiconazole is one of the triazole fungicides Electrophoresis 2009,30,[1976][1977][1978][1979][1980][1981][1982] and has hydrophobicity close to the selected triazole fungicide used in this study. Accordingly, the BGE composition used in this study for chiral selector screening is similar to the one used in the earlier study [39]. Separation using MEKC was performed by adding micelles to the running buffer at 40 mM SDS at pH 3.0.…”

Section: Resultsmentioning

confidence: 99%

“…At acidic pH, sweeping CD-MEKC separation was achieved with 40 mM SDS and at pH 7, CD-MEKC separation was achieved with 50 mM SDS and above. To the BGE, methanol-acetonitrile 10%:5% v/v was added as organic modifiers at the same composition used in the previous study [39].…”

Section: Resultsmentioning

confidence: 99%

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Simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers by CD‐modified MEKC

et al. 2009

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An efficient method for the simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers was developed by CD-modified MEKC using a dual mixture of neutral CDs as chiral selector. Three neutral CDs namely hydroxypropyl-beta-CD, hydroxypropyl-gamma-CD, and gamma-CD were tested as chiral selectors at different concentrations ranging from 10, 20, 30 and 40 mM, but enantiomers of the studied fungicides were not completely separated. The best dual chiral recognition mode for the simultaneous separation of cyproconazole, bromuconazole, and diniconazole enantiomers was achieved with a mixture of 27 mM hydroxypropyl-beta-CD and 3 mM hydroxypropyl-gamma-CD in 25 mM phosphate buffer (pH 3.0) containing 40 mM SDS to which methanol-acetonitrile (10%:5% v/v) was added as organic modifiers. The best separation was based on the appearance of 10 peaks simultaneously, with good resolution (R(s) 1.1-15.9), and peak efficiency (N>200,000). Good repeatabilities in the migration time, peak area, and peak height were obtained in terms of RSD ranging from (0.72 to 1.06)%, (0.39 to 3.49)%, and (1.90 to 4.84)%, respectively.

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Section: Resultssupporting

confidence: 72%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers by CD‐modified MEKC

et al. 2009

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“…However, it is usually difficult to achieve an enrichment factor larger than 100 due to the limited ratio of volumes before and after enrichment. For on-line preconcentration, a variety of schemes, such as isotachophoresis [22,23], transient isotachophoresis [24][25][26][27], field-amplified sample stacking [28,29], large-volume sample stacking [30][31][32][33][34][35][36], and sweeping [37][38][39] have been used. However, interference from chiral selectors often causes complications in the on-line preconcentration process [23,36].…”

Section: Introductionmentioning

confidence: 99%

Direct chiral analysis of primary amine drugs in human urine by single drop microextraction in‐line coupled to CE

et al. 2009

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Three-phase single drop microextraction (SDME) was in-line coupled to chiral CE of weakly basic amine compounds including amphetamine. SDME was used for the matrix isolation and sample preconcentration in order to directly analyze urine samples with the minimal pretreatment of adding NaOH. A small drop of an acidic aqueous acceptor phase covered with a thin layer of octanol was formed at the tip of a capillary by simple manipulation of the liquid handling functions of a commercial CE instrument. While the saline matrix of the urine sample was blocked by the octanol layer, the basic analytes in a basic aqueous donor phase were concentrated into the acidic acceptor drop through the octanol layer by the driving force of the pH difference between the two aqueous phases. The enantiomers of the enriched amines were resolved by using (+)-(18-crown-6)-tetracarboxylic acid as a chiral selector for the subsequent CE separation. From 10 min SDME with the agitation of the donor phase by a small stirrer retrofit to the CE instrument, enrichment factors were about a 1000-fold, yielding the LOD of 0.5 ng/mL for amphetamine. This low LOD value as well as the convenience of in-line coupled SDME make the proposed scheme well suited for the demanding chiral analysis of amphetamine-type stimulants.

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Pesticides (New Generation) and Related Compounds, Analysis of

Picó

2009

Encyclopedia of Analytical Chemistry

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Miscellaneous pesticides and related compounds comprise substances that can neither be included in the classical chemical category of pesticides nor classified by their mode of action. They are a heterogeneous group of substances, the most representative of which are macrocyclic lactones, chloronicotinyls, tetranortriterpenoids, ammonium quaternary salts, dinitroanilines, acetamides, oximes, triazoles, and pyridine‐based molecules. The pesticides covered in this article have hardly changed in the last years. However, their analytical determination has undergone significant improvements. This article provides a well‐defined and critical compilation of the sample treatment and clean‐up procedures, as well as determination techniques applied to miscellaneous pesticides. The new approaches in sample preparation in environmental matrices, such as air, water, soil, food and biological samples, are described. Analytical techniques for characterizing these compounds, which mostly include gas chromatography (GC) and high‐performance liquid chromatography (HPLC) coupled to mass spectrometry (MS), are discussed. Both techniques have almost completely displaced other chromatographic methods. However, in the frontier between chemical and biological techniques, the development of biosensor techniques is very promising. Here, analytical methods applied to the field of real samples are also presented.

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On-line preconcentration and chiral separation of propiconazole by cyclodextrin-modified micellar electrokinetic chromatography

Cited by 46 publications

References 24 publications

Simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers by CD‐modified MEKC

Simultaneous enantioseparation of cyproconazole, bromuconazole, and diniconazole enantiomers by CD‐modified MEKC

Direct chiral analysis of primary amine drugs in human urine by single drop microextraction in‐line coupled to CE

Pesticides (New Generation) and Related Compounds, Analysis of

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