Sweeping: concentration mechanism and applications to high-sensitivity analysis in capillary electrophoresis

Quirino, Joselito P.; Kim, Jong-Bok; Terabe, Shigeru

doi:10.1016/s0021-9673(01)01499-6

Cited by 239 publications

(138 citation statements)

References 46 publications

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“…Although the first applications were performed using a sample matrix with the same conductivity than the separation buffer [94], this sample matrix may have different conductivity [96] but it is very important that the sample matrix does not contain the pseudostationary phase, which is the component producing the preconcentration of the analyte by sweeping the sample matrix. Fig.…”

Section: On-column Preconcentration Techniques In Sensitive Chiral Anmentioning

confidence: 99%

Sensitive chiral analysis by capillary electrophoresis

García-Ruiz

Marina

2006

Electrophoresis

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Sensitive chiral analysis by capillary electrophoresisIn this review, an updated view of the different strategies used up to now to enhance the sensitivity of detection in chiral analysis by CE will be provided to the readers. With this aim, it will include a brief description of the fundamentals and most of the recent applications performed in sensitive chiral analysis by CE using offline and online sample treatment techniques (SPE, liquid-liquid extraction, microdialysis, etc.), on-column preconcentration techniques based on electrophoretic principles (ITP, stacking, and sweeping), and alternative detection systems (spectroscopic, spectrometric, and electrochemical) to the widely used UV-Vis absorption detection.

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Section: On-column Preconcentration Techniques In Sensitive Chiral Anmentioning

confidence: 99%

Sensitive chiral analysis by capillary electrophoresis

García-Ruiz

Marina

2006

Electrophoresis

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“…The shorter the swept zone length is, the more efficiently the analytes can be focused. According to [15], l sweep was determined by two factors: the injected sample plug length and the retention factor. Figure 1 shows the effect of the sample plug injection time on the focused efficiency.…”

Section: Sweeping Modementioning

confidence: 99%

“…Nevertheless, CD-MEKC suffers from poor detection sensitivity due to the short optical path length and low injected sample volume (nL) [15]. Therefore, the direct analysis of trace amounts of analytes in the real samples with CD-MEKC is difficult.…”

Section: Introductionmentioning

confidence: 99%

Comparison of two capillary electrophoresis online stacking modes by analysis of polycyclic aromatic hydrocarbons in airborne particulates

Song

Peng

Lin

2006

J of Separation Science

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Original PaperComparison of two capillary electrophoresis online stacking modes by analysis of polycyclic aromatic hydrocarbons in airborne particulates Naphthalene, fluorene, pyrene, anthracene, phenanthrene, and chrysene were successfully separated by CD-modified MEKC (CD-MEKC) using 20 mM borate (pH 9.0) containing 90 mM SDS and 75 mM b-CD. Two online stacking methods, i. e., sweeping and field-enhanced sample injection (FESI), were explored to enhance the detection sensitivity. The influences of some crucial parameters in sweeping and FESI procedures were investigated. For FESI method, a plug of water and low-conductivity sample matrix was used to increase the stacking efficiency. Compared with the sweeping method, FESI can increase the sensitivity in the range of 10 -20-fold. The proposed method was used for the analysis of polycyclic aromatic hydrocarbons in airborne particulates.

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“…Therefore, the sweeping time t s and the migration time t m need to satisfy the following condition, (8) By substituting Equations 5-7 into Equation 8, l SB needs to satisfy the following condition, (9) For a long injection time, the maximum of sample solution length may have been reached, and then l SB in Equation 9 is replaced by l SB,max , which is equal to Lx max . (10) where x max is determined by Equation 3, and β is the critical ratio of the sample plug length to the entire capillary length.…”

Section: Theoretical Considerationmentioning

confidence: 99%

Unlimited-Volume Electrokinetic Stacking Injection in Sweeping Capillary Electrophoresis Using a Cationic Surfactant

et al. 2006

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Sweeping is an effective and convenient way for online sample preconcentration in micellar electrokinetic chromatography (MEKC). The usual procedure includes a hydrodynamic injection step carried out by applying pressure to the sample vial followed by the subsequent sweeping and separation processes. The injected sample volume is limited by the dimensions of the capillary because a part of the capillary has to be left free of sample solution for the subsequent sweeping and separation steps. In addition, when a short capillary, such as 4-10 cm, is used for sweeping, the injected sample volume is small even if the entire capillary is filled with sample solution. In order to solve this problem, an electrokinetic stacking injection (EKSI) scheme was developed by using a cationic surfactant, dodecyltrimethylammonium bromide, for sweeping in capillary electrophoresis. An experimental model was proposed, and the entire process was theoretically analyzed. According to the theoretical discussion, the optimal conditions for two model analytes, 5-carboxyfluorescein (5-FAM) and sodium fluorescein (FL), were experimentally determined. The injected sample plug lengths for 5-FAM and FL under 20.1 kV for 60 min were experimentally estimated as 836 and 729 cm, corresponding to 28-and 24-fold the effective capillary length, respectively. The EKSI scheme resulted in increased detection factors for 5-FAM and FL of 4.5×10 3 and 4.0×10 3 using 60-minute injection relative to a traditional pressure injection.

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Sweeping: concentration mechanism and applications to high-sensitivity analysis in capillary electrophoresis

Cited by 239 publications

References 46 publications

Sensitive chiral analysis by capillary electrophoresis

Sensitive chiral analysis by capillary electrophoresis

Comparison of two capillary electrophoresis online stacking modes by analysis of polycyclic aromatic hydrocarbons in airborne particulates

Unlimited-Volume Electrokinetic Stacking Injection in Sweeping Capillary Electrophoresis Using a Cationic Surfactant

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