Effect of pH and ions in the sample on stacking in capillary electrophoresis

Friedberg, Michael A.; Hinsdale, Mark E.; Shihabi, Zak K.

doi:10.1016/s0021-9673(97)00582-7

Cited by 53 publications

(33 citation statements)

References 9 publications

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“…Relations 1:3, 1:1 and 3:1 as well as pure acetonitrile or separation buffer alone were tested. Among them, pure acetonitrile yielded the highest signal to noise ratios and consequently, the lowest LODs, in good agreement with that observed by other authors [31][32][33]. In our case, by using acetonitrile alone, the sample could be injected in the longer CE-MS capillary up to 100 seconds (that represents approximately 3.7% of the total volume of the capillary).…”

Section: Ce-ms With Normal Stackingsupporting

confidence: 91%

Analysis of pesticides in soy milk combining solid‐phase extraction and capillary electrophoresis‐mass spectrometry

Hernández-Borges

Rodríguez‐Delgado

García-Montelongo

et al. 2005

J of Separation Science

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In this work, the determination of a group of triazolopyrimidine sulfoanilide herbicides (cloransulam-methyl, metosulam, flumetsulam, florasulam and diclosulam) in soy milk by capillary electrophoresis-mass spectrometry (CE-MS) is presented. The main electrospray interface (ESI) parameters (nebulizer pressure, dry gas flow rate, dry gas temperature and composition of the sheath liquid) are optimized using a central composite design. To increase the sensitivity of the CE-MS method, an off-line sample preconcentration procedure based on solid-phase extraction (SPE) is combined with an on-line stacking procedure (i.e. normal stacking mode, NSM). Samples could be injected up to 100 seconds, providing limits of detection (LODs) down to 74 μg/L, i.e., in the low ppb level, with relative standard deviation values (RSD, %) between 3.8% and 6.4% for peak areas for the same day, and between 6.5% and 8.1% for three different days. The usefulness of the optimized SPE-NSM-CE-MS procedure is demonstrated through the sensitive quantification of the selected pesticides in soy milk samples.

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Section: Ce-ms With Normal Stackingsupporting

confidence: 91%

Analysis of pesticides in soy milk combining solid‐phase extraction and capillary electrophoresis‐mass spectrometry

Hernández-Borges

Rodríguez‐Delgado

García-Montelongo

et al. 2005

J of Separation Science

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“…Transient (pseudo) tITP conditions can be achieved by inclusion of a low conductivity organic solvent, commonly ACN, into the saline sample [90][91][92][93][94][95][96][97] (see also [18] for an overview). Note that such samples typically occur after ACN deproteinization of serum.…”

Section: Titp Stacking In the Presence Of Organic Solventmentioning

confidence: 99%

Recent advances of transient isotachophoresis‐capillary electrophoresis in the analysis of small ions from high‐conductivity matrices

2006

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Since its invasion into the field of small ion analysis, quantitation of trace ionic analytes has always been a challenging task for CE, especially when dealing with highly saline samples. This review summarizes the method's progress and significant developments in the area due to its combination with on-line preconcentration by transient ITP (tITP). Principles of tITP stacking in high-conductivity solutions and operational preconcentration modes are considered. The most important application areas covered in this review include the analysis of seawater and biological fluids (urine, serum, etc.). Examples cited in this review demonstrate that tITP-CE is now on a certain way of becoming a recognized technique when the determination of trace ionic species in loaded matrices is the aim.

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“…Shihabi et al demonstrated the ACN-salt stacking (ASS) to determine peptides [19], insulin [20], and anions [21], while Kong et al [22] used ASS to assay low concentration glutathione in plasma of a diabetic nephropathy patient. This method permits a larger volume sample injection (about 10-30% of the capillary volume) than in the normal CZE mode (within 1-2% of the capillary volume).…”

Section: Introductionmentioning

confidence: 99%

Simultaneous enantioseparation and sensitivity enhancement of basic drugs using large‐volume sample stacking

et al. 2007

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Simultaneous enantioseparation with sensitive detection of four basic drugs, namely methoxamine, metaproterenol, terbutaline and carvedilol, using a 20-mum ID capillary with native beta-CD as the chiral selector was demonstrated by the large-volume sample stacking method. The procedure included conventional sample loading either hydrodynamically or electrokinetically at longer injection times without polarity switching and EOF manipulation. In comparison to conventional injections, depending on the analyte, about several hundred- and a thousand-fold sensitivity enhancement was achieved with the hydrodynamic and the electrokinetic injections, respectively. The simple method developed was applied to the analysis of racemic analytes in serum samples and better recovery was achieved using hydrodynamic injection than electrokinetic injection.

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Effect of pH and ions in the sample on stacking in capillary electrophoresis

Cited by 53 publications

References 9 publications

Analysis of pesticides in soy milk combining solid‐phase extraction and capillary electrophoresis‐mass spectrometry

Analysis of pesticides in soy milk combining solid‐phase extraction and capillary electrophoresis‐mass spectrometry

Recent advances of transient isotachophoresis‐capillary electrophoresis in the analysis of small ions from high‐conductivity matrices

Simultaneous enantioseparation and sensitivity enhancement of basic drugs using large‐volume sample stacking

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