PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9823717

On-column sample preconcentration using sample matrix switching and field amplification for increased sensitivity of capillary electrophoretic analysis of physiological samples.

Y Zhao·K McLaughlin·C E Lunte
View original source ↗Export metadata ↓

Abstract

An on-line sample concentration method using sample matrix switching and field amplification peak stacking has been developed. A microbore LC guard column is used to slightly retain the analytes in order to switch from a high ionic strength sample matrix (the physiological fluid) to a low ionic strength matrix (the LC mobile phase). The eluted LC peak is then trapped in a CE system and preconcentrated by field amplification peak stacking. The concentrated sample peak is then analyzed by CE. Compared to normal hydrodynamic injection, the sensitivity was increased by more than 500-fold without loss in resolution. A limit of detection of less than 10 nM for a physiological sample was achieved using UV adsorption detection. This method can be used for negatively or positively charged analytes.

Explore related subjects

BupivacaineElectromagnetic FieldsElectrophoresis, CapillaryHydrogen-Ion ConcentrationMicrodialysisSpectrophotometry, UltravioletJournal ArticleResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Y Zhao, K McLaughlin, C E Lunte. 1998-11-01. On-column sample preconcentration using sample matrix switching and field amplification for increased sensitivity of capillary electrophoretic analysis of physiological samples.. https://doi.org/10.1021/ac980427c

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1998

Thermal behavior of human melanoma cell line in vitro and enhancement of hyperthermic response by bupivacaine.

The effect of hyperthermia and bupivacaine, alone and in combination, on the clonogenic activity of a human melanoma cell line was investigated. The time-temperature relationship of exponentially growing cells was defined in the range of 41-45 degrees C. All the survival curves were exponential and the Arrhenius plot was linear over the temperature range tested. The survival curve of bupivacaine-treated cells was also exponential after an initial shoulder. Bupivacaine affected cell survival mainly through an ATP depletion because of deep alterations of mitochondria, essentially due to changes in the physical state of membrane lipids. The analysis of the interaction between hyperthermia and bupivacaine, performed with an isobolar method, demonstrated a synergism of response at all combinations tested, but only with simultaneous exposure. Such a response did not depend on an impairment of the energy-yielding processes, but may be ascribed to combined effects of both agents on cell structure and function. The hyperthermic enhancement achieved by low bupivacaine concentrations allowed to achieve a preestablished cell killing with a reduced exposure time (e.g., 50 min) and with a temperature (42 degrees C) generally accepted as clinically achievable. Therefore, a combined modality in which local treatment with bupivacaine was coupled to local heating could result in high local damage with reduced systemic complications.

Bupivacaine↗