Journal•ISSN: 1040-7685
Journal of Microcolumn Separations
Wiley-Blackwell
About: Journal of Microcolumn Separations is an academic journal. The journal publishes majorly in the area(s): Capillary electrophoresis & Supercritical fluid chromatography. It has an ISSN identifier of 1040-7685. Over the lifetime, 756 publications have been published receiving 17249 citations.
Topics: Capillary electrophoresis, Supercritical fluid chromatography, Gas chromatography, Micellar electrokinetic chromatography, Column chromatography
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TL;DR: The theory and practice of a novel approach for sample enrichment, namely the application of stir bars coated with the sorbent polydimethylsiloxane (PDMS) and referred to as stir bar sorptive extraction (SBSE) are presented in this paper.
Abstract: The theory and practice of a novel approach for sample enrichment, namely the application of stir bars coated with the sorbent polydimethylsiloxane (PDMS) and referred to as stir bar sorptive extraction (SBSE) are presented. Stir bars with a length of 10 and 40 mm coated with 55 and 219 μL of PDMS liquid phase, respectively were applied. The 10-mm stir bars are best suited for stirring sample volumes from 10 up to 50 mL whereas 40-mm stir bars are more ideal for sample volumes up to 250 mL. Depending on sample volume and the stirring speed, typical stirring times for equilibration are between 30 and 60 min. The performance of SBSE is illustrated with the analysis of volatile and semivolatile micropollutants from aqueous samples. Detection limits using mass selective detection are in the low ng/L range for a wide selection of analytes from the EPA priority pollutant lists including analytes ranging in volatility from 1,1,1-trichloroethane to chrysene. For the extraction of selected compounds from 200-mL samples, detection limits below 0.1 ng/L are reached in the selected ion monitoring mode. A comparison between SBSE and solid-phase microextraction is made. ©1999 John Wiley & Sons, Inc. J Micro Sep 11: 737–747, 1999
1,362 citations
TL;DR: In this article, the authors used micellar electrokinetic chromatography and bile salts as surfactants to separate optical isomeric drugs under neutral or alkaline conditions.
Abstract: Separation of optical isomeric drugs using micellar electrokinetic chromatography and bile salts as surfactants was studied. Optical isomers of diltiazem hydrochloride, trimetoquinol hydrochloride, and other drugs were separated successfully using chiral bile salts under neutral or alkaline conditions. Capacity factors were determined from the migration times of the solute, the micelle, and methanol. The effects of bile salt species or structures and of the pH value of the buffer solution were investigated. A possible chiral separation mechanism is suggested.
155 citations
TL;DR: In this paper, the authors demonstrate that equivalent electroosmotic flows can be achieved using different buffer types if the ionic strength is equal in the two systems, and the effects of the addition of acetonitrile and several different alcohols on electro-somatic flow are also examined.
Abstract: Solute migration in capillary electrophoresis is the sum of the molecularly specific electrophoretic mobility and the electric-field-induced solvent flow (electroosmosis). This solvent flow is an important component of capillary electrophoresis and has been linked to resolution and automation aspects of this technique. This work demonstrates that equivalent electroosmotic flows can be achieved using different buffer types if the ionic strength is equal in the two systems. The effects of the addition of acetonitrile and several different alcohols on electroosmotic flow are also examined. The data suggest a unique surface effect of alcohols on the observed electroosmotic flow.
155 citations
TL;DR: In this article, a microfabricated device with C18-coated channels was used to demonstrate on-chip solid phase extraction, and sample solutions containing a neutral dye were enriched and eluted in less than 4 min.
Abstract: A microfabricated device with C18-coated channels was used to demonstrate on-chip solid phase extraction. Sample solutions containing a neutral dye were enriched and eluted in less than 4 min. Distinct elution peaks with good signal-to-noise ratios were obtained even for highly dilute samples. The gain in concentration estimated from the enrichment and elution volumes was 80-fold. ©2000 John Wiley & Sons, Inc. J Micro Sep 12: 93–97, 2000
142 citations
TL;DR: In this article, a headspace sorptive extraction (HSSE) method was proposed to enrich analytes from the headspace of aqueous or solid samples, referred to as HSSE.
Abstract: A new approach for sorptive enrichment of analytes from the headspace of aqueous or solid samples, referred to as headspace sorptive extraction (HSSE) is described. The technique implies the sorption of volatile and semivolatile compounds into a large amount of polydimethylsiloxane (ca. 50 mg) placed on a glass rod support. The polydimethylsiloxane (PDMS) coated rod is fixed in the head of a closed vial or erlenmeyer and the sample is equilibrated for 30–60 min. The PDMS coated glass bar is then thermally desorbed on-line with capillary gas chromatography–mass spectroscopy (GC–MS). Using a large amount of sorptive phase highly volatile compounds can be efficiently enriched and compared to solid phase microextraction on a 100 μm PDMS fiber where a significant increase in sensitivity is achieved. Limits of detection are in the ng L−1 (ppt) range. The potential of HSSE is illustrated with the analysis of some food samples. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 577–584, 2000
142 citations