Multivariate evaluation of organic modifier effects on the separation performance of peptides in micellar electrokinetic chromatography

Þorsteinsdóttir, Margrét; Ringbom, C.; Westerlund, Douglas; Andersson, Greger; Kaufmann, Peter

doi:10.1016/s0021-9673(98)00926-1

Cited by 21 publications

(12 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it was also observed that the effects of ACN and THF on EOF differ from those of other organic modifiers [33]. Similar trends were also reported by Seifar et al [34] and Thorsteinsdottir et al [35] when SDS micelles were used in combination with ACN. They hypothesized that the observed decrease in migration time at higher level of ACN content might be due to a change in the micellar structure.…”

Section: Influence Of Organic Modifier On Migration Time and Chiral Rsupporting

confidence: 80%

Application of polymeric surfactants in micellar electrokinetic chromatography‐electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

et al. 2006

View full text Add to dashboard Cite

Application of polymeric surfactants in micellar electrokinetic chromatographyelectrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs Chiral micellar EKC (CMEKC) coupled to ESI-MS using polymeric surfactants as pseudostationary phases is investigated for simultaneous enantioseparation of two benzodiazepines, (6)-oxazepam ((6)-OXA) and (6)-lorazepam ((6)-LOR), and one benzoxazocine, (6)-nefopam ((6)-NEF). First, enantioselectivity and electrospray sensitivity of six chiral polymeric surfactants for all three chiral compounds are compared. Second, using poly(sodium N-undecenoyl-L-leucinate) as pseudostationary phase, the organic modifiers (methanol (MeOH), isopropanol, and ACN) are added into the running buffer to further improve chiral resolution (R S ). Next, a CMEKC-ESI-MS method for the simultaneous enantioseparation of two benzodiazepines is further developed by using a dipeptide polymeric surfactant, poly(sodium N-undecenoxy carbonyl-L,L-leucyl-valinate) (poly-L,L-SUCLV). The CMEKC conditions including nebulizer pressure, capillary length, ammonium acetate concentration, pH, poly-L,L-SUCLV concentration, and capillary temperature were optimized to achieve maximum chiral R S and highest sensitivity of MS detection. The spray chamber parameters (drying gas temperature and drying gas flow rate) as well as sheath liquid conditions (MeOH content, pH, flow rate, and ionic strength) were found to significantly influence MS S/N of both (6)-OXA and (6)-LOR. Finally, a comparative study between simultaneous UV and MS detection showed high plate numbers, better chiral R S , and enhanced detectability with CMEKC-MS. However, speed of analysis was faster using CMEKC-UV.

show abstract

Section: Influence Of Organic Modifier On Migration Time and Chiral Rsupporting

confidence: 80%

Application of polymeric surfactants in micellar electrokinetic chromatography‐electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

et al. 2006

View full text Add to dashboard Cite

show abstract

“…11, the six peptides can be separated with baseline resolution in less than 10 min. Since the pI value of the selected small peptides is 6.1 [36], the majority of peptides were nearly neutral under the selected separation conditions. Therefore, the separation mechanism of the six peptides was mainly based on the HI.…”

Section: Small Hydrophilic Peptidesmentioning

confidence: 99%

Sulfoalkylbetaine‐based monolithic column with mixed‐mode of hydrophilic interaction and strong anion‐exchange stationary phase for capillary electrochromatography

et al. 2010

View full text Add to dashboard Cite

A novel monolithic stationary phase with mixed mode of hydrophilic and strong anion exchange (SAX) interactions based on in situ copolymerization of pentaerythritol triacrylate (PETA), N,N-dimethyl-N-methacryloxyethyl N-(3-sulfopropyl) ammonium betaine (DMMSA) and a selected quaternary amine acrylic monomer was designed as a multifunctional separation column for CEC. Although the zwitterionic functionalities of DMMSA and hydroxy groups of PETA on the surface of the monolithic stationary phase functioned as the hydrophilic interaction (HI) sites, the quaternary amine acrylic monomer was introduced to control the magnitude of the EOF and provide the SAX sites at the same time. Three different quaternary amine acrylic monomers were tested to achieve maximum EOF velocity and highest plate count. The fabrication of the zwitterionic monolith (designated as HI and SAX stationary phase) was carried out when [2-(acryloyloxy)ethyl]trimethylammonium methylsulfate was used as the quaternary amine acrylic monomer. The separation mechanism of the monolithic column was discussed in detail. For charged analytes, a mixed mode of HI and SAX was observed by studying the influence of mobile phase pH and salt concentration on their retentions on the poly(PETA-co-DMMSA-co-[2-(acryloyloxy)ethyl]trimethylammonium methylsulfate) monolithic column. The optimized monolith showed good separation performance for a range of polar analytes including nucleotides, nucleic acid bases and nucleosides, phenols, estrogens and small peptides. The column efficiencies greater than 192 000 theoretical plates/m for estriol and 135 000 theoretical plates/m for charged cytidine were obtained.

show abstract

“…1. All the peptides have pI s of 5.35 -6.1 according to the different literature resources [12,24,25], except the ones containing arginine and lysine (whose pI values were 9.8 [24]), so they are positively charged and migrated before EOF at low pH. It can be seen from (10) were not separated that well at pH a3, while at pH A3.7 peptides Des-tyr 1 -methionine enkephalin (D) (4) and LE (6), methionine enkephalin (ME) (8) and D-AL (9) comigrated.…”

Section: Running Buffer Phmentioning

confidence: 99%

Separation and determination of enkephalin-related peptides using capillary electrophoresis

et al. 2005

View full text Add to dashboard Cite

CZE with UV-absorption detection has been used for the separation and determination of enkephalin-related peptides. The experimental conditions, such as pH and concentration of running buffer, applied voltage, injection method, and time, were investigated in detail. Excellent separation efficiency could be obtained for ten enkephalin-related peptides with a 50 microm (ID) x 58 cm capillary using sodium dihydrogen phosphate as the running buffer (pH 3.11) when 20 kV of applied voltage was used. The concentration detection limits were found to be in the range of 0.31-1.94 microg/mL (defined as S/N = 3). The proposed method has been applied to analyze the spiked cerebrospinal fluid (CSF) sample, and the results showed that CZE is a powerful technique for separation and detection of the above biological peptides.

show abstract

Multivariate evaluation of organic modifier effects on the separation performance of peptides in micellar electrokinetic chromatography

Cited by 21 publications

References 37 publications

Application of polymeric surfactants in micellar electrokinetic chromatography‐electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

Application of polymeric surfactants in micellar electrokinetic chromatography‐electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

Sulfoalkylbetaine‐based monolithic column with mixed‐mode of hydrophilic interaction and strong anion‐exchange stationary phase for capillary electrochromatography

Separation and determination of enkephalin-related peptides using capillary electrophoresis

Contact Info

Product

Resources

About