Contemporary sample stacking in CE: A sophisticated tool based on simple principles

Malá, Zdena; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

doi:10.1002/elps.200600397

Cited by 128 publications

(87 citation statements)

References 126 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TITP is a technique in which solutes are initially concentrated by ITP and then separated by capillary zone electrophoresis (CZE) in a single capillary. [11][12][13][14] In other words, a heterogeneous system of electrolytes satisfying Eq. (2) exists transiently, followed by the restoration of a homogeneous BGE system for CZE.…”

Section: +mentioning

confidence: 99%

Isotachophoretically Assisted On-Line Complexation of Trace Metal Ions in a Highly Saline Matrix for Capillary Electrophoresis

Kim¹,

Choi²,

Cho³

et al. 2012

Bulletin of the Korean Chemical Society

View full text Add to dashboard Cite

Trace metal ions such as Cd 2+, Ni 2+, and Zn 2+ in a highly saline sample were subjected to on-line complexation with 4-(2-thiazolylazo) resorcinol (TAR) dissolved in a background electrolyte (BGE) under transient isotachophoresis (TITP) conditions. A long plug of the saline sample, containing the trace metal ions but devoid of TAR, was injected into a coated capillary filled with a BGE composed of 150 mM 2-(cyclohexylamino) ethanesulfonic acid (CHES) and 110 mM triethylamine (TEA) at pH 9.7. Since the electrophoretic mobility of TAR fell between the mobilities of the anionic leading electrolyte (Cl − in the sample) and the anionic terminating background electrolyte (CHES − ), a highly concentrated zone of TAR from the BGE was formed at the rear of the sample matrix and then the metal cations toward the cathode were swept by isotachophoretically assisted on-line complexation (IAOC) between the metal ions and the isotachophoretically stacked TAR. As a result, anionic metal-TAR complexes were formed efficiently, which satisfy the TITP conditions between Cl − and CHES − . The enrichment factors of metal ions including Cd 2+ were up to 780-fold compared to a conventional CZE mode using absorbance detection. The detection limits were 17 nM, 15 nM, and 27 nM for Ni 2+, Zn 2+, and Cd 2+ in a 250 mM NaCl matrix, respectively. Our method was successfully applied to the analysis of urine samples without desalting.

show abstract

Section: +mentioning

confidence: 99%

Isotachophoretically Assisted On-Line Complexation of Trace Metal Ions in a Highly Saline Matrix for Capillary Electrophoresis

Kim¹,

Choi²,

Cho³

et al. 2012

Bulletin of the Korean Chemical Society

View full text Add to dashboard Cite

show abstract

“…This has been proved in numerous tITP-CE applications to seawater and highly saline biological samples (including urine) [9]. The mechanism and operational procedures of tITP stacking have been detailed in a large number of literatures (see [10][11][12] to mention a few). As a powerful enrichment tool, tITP has been applied to a range of small ionic urinary analytes: metal cations [13,14], inorganic anions [15][16][17][18][19], organic acids [19][20][21], etc., by accomplishing the sample-focusing conditions in a sampleinduced mode or by introducing the leading electrolyte (LE) as a separate zone.…”

Section: Introductionmentioning

confidence: 98%

Sensitive profiling of biogenic amines in urine using CE with transient isotachophoretic preconcentration

Okada

Timerbaev

et al. 2009

J of Separation Science

View full text Add to dashboard Cite

A transient ITP-CZE system is proposed for the determination of biogenic amines in urine. The complete separation and identification of dopamine, tyramine (TA), tryptamine (T), serotonin, epinephrine, norepinephrine, and normetanephrine have been achieved in a twofold diluted urine sample (in which the analytes were below the LODs by normal CZE). The tITP preconcentration conditions were created by introducing a 30 mM solution of NaOH, containing 0.1% hydroxypropylcellulose (pH 6.5 adjusted with MES), and 0.1 M HCl before and after the sample zone to work as leading and terminating electrolytes, respectively. This allowed the LODs of direct UV absorption detection to be decreased down to the 10 -8 M level that is comparable with the sensitivity thresholds of LIF detection or inline SPE-CE. The RSDs of migration time and peak area for realbiofluid analysis were in the range of 0.1-4.5% and 0.8-16% (n 5 3), respectively. Quantification of dopamine, TA, T, and serotonin was performed using internal calibration. To the best of our knowledge, this is the first report on probing urinal biogenic amines and their metabolites by tITP-CZE.

show abstract

“…A variety of approaches have been used, including stacking (Malá et al, 2007;Siri et al, 2003) and sweeping (Pyell, 2001) to virtually increase the concentration of the sample. Laser-induced fluorescence (LIF) is a powerful tool which has been widely employed by a number of workers (Johnson and Landers, 2004;Lacroix et al, 2005) to increase the sensitivity.…”

Section: Introductionmentioning

confidence: 99%

Improving detection in capillary electrophoresis with laser induced fluorescence via a bubble cell capillary and laser power adjustment

Rodat

Gavard

Couderc

2008

Biomedical Chromatography

View full text Add to dashboard Cite

Bubble cells have been frequently employed in capillary electrophoresis (CE) to increase the light path length with UV detection to provide an increase in the observed sensitivity of CE; however this approach has not been commonly used for laser-induced fluorescence detection (LIF) with CE. In this paper we study the influence of laser power on the sensitivity of detection in using conventional and enlarged fused silica capillaries for CE with LIF. When using the bubble cell capillary, the laser power must be decreased relative to use of the conventional capillary to reduce the effects of photodegradation of the species being illuminated by the laser. Even though the light intensity was decreased, an increase in sensitivity of detection was observed for most compounds when a bubble cell was used. This increase ranged from a factor of 8 for riboflavin (410 nm excitation) to 3.2 for most aromatic compounds (266 nm excitation), when using a 3x bubble cell compared with a conventional capillary. The bubble cell capillary was used for native detection of IgG by LIF at 266 nm. A limit of detection of 60 ng mL(-1) was obtained from a 20 pg injection, which was 40 times more sensitive than silver staining in conventional SDS/PAGE.

show abstract

Contemporary sample stacking in CE: A sophisticated tool based on simple principles

Cited by 128 publications

References 126 publications

Isotachophoretically Assisted On-Line Complexation of Trace Metal Ions in a Highly Saline Matrix for Capillary Electrophoresis

Isotachophoretically Assisted On-Line Complexation of Trace Metal Ions in a Highly Saline Matrix for Capillary Electrophoresis

Sensitive profiling of biogenic amines in urine using CE with transient isotachophoretic preconcentration

Improving detection in capillary electrophoresis with laser induced fluorescence via a bubble cell capillary and laser power adjustment

Contact Info

Product

Resources

About