In-line SPE-CE using a fritless bead string design--application for the analysis of organic sulfonates including inline SPE-CE-MS for APTS-labeled glycans.

Despite many advantages like high separation efficiency CE comprises the main limitation of low concentration sensitivity, when compared to HPLC. In-line SPE is an efficient way to increase concentration sensitivity. Here, a fritless in-line-SPE-CE-MS method was developed in order to analyze anions of strong acids.

Capillary electrophoresis/mass spectrometry of APTS-labeled glycans for the identification of unknown glycan species in capillary electrophoresis/laser-induced fluorescence systems.

The examination of protein glycosylation is of high importance, especially in the (bio)pharmaceutical sector. The analysis of protein glycosylation is conducted routinely in high performance by capillary electrophoresis with laser-induced fluorescence (CE/LIF) using 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled glycans. In this work we present an optimized capillary electrophoresis/time-of-flight mass spectrometry (CE/TOF-MS) methodology for these labeled glycans, which combines the high separation performance of CE with the high resolution, accuracy, and speed of TOF-MS for eased glycan identification.

Analysis of native and APTS-labeled N-glycans by capillary electrophoresis/time-of-flight mass spectrometry.

The glycosylation of proteins is of particular interest in biopharmaceutical applications. The detailed characterization of glycosylation based on the released carbohydrates is mandatory since the protein stability, folding, and efficacy are strongly dependent on the structural diversity inherent in the glycan moieties of a glycoprotein. For glycan pattern analysis, capillary electrophoresis with laser-induced fluorescence using 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled glycans is used frequently.

Interlaboratory study on differential analysis of protein glycosylation by mass spectrometry: the ABRF glycoprotein research multi-institutional study 2012.

One of the principal goals of glycoprotein research is to correlate glycan structure and function. Such correlation is necessary in order for one to understand the mechanisms whereby glycoprotein structure elaborates the functions of myriad proteins. The accurate comparison of glycoforms and quantification of glycosites are essential steps in this direction.

Isomerization and epimerization of the aspartyl tetrapeptide Ala-Phe-Asp-GlyOH at pH 10-A CE study.

Isomerization and enantiomerization of Asp in the tetrapeptide Ala-Phe-Asp-GlyOH are studied at pH 10 and 80°C as well as 25°C. CE-MS allowed the distinction between α-Asp and β-Asp linkages in degradation products based on the ratio of the b and y fragment ions. Besides isomerization and enantiomerization of Asp, enantiomerization of Ala and Phe was also observed at both temperatures by chiral amino acid HPLC analysis using Marfey's reagent for derivatization.

The selective determination of sulfates, sulfonates, and phosphates in urine by capillary electrophoresis/mass spectrometry.

Metabolite identification and metabolite profiling are of major importance in the pharmaceutical and clinical context. However, anions of biological relevance such as sulfates, sulfonates, and phosphates are rarely included in common techniques for metabolite studies. In this protocol, we demonstrate a unique method to selectively determine these anions.

Capillary electrophoresis/mass spectrometry relevant to pharmaceutical and biotechnological applications.

Advanced analytical techniques play a crucial role in the pharmaceutical and biotechnological field. In this context, capillary electrophoresis/mass spectrometry (CE/MS) has attracted attention due to efficient and selective separation in combination with powerful detection allowing identification and detailed characterization. Method developments and applications of CE/MS have been focused on questions not easily accessible by liquid chromatography/mass spectrometry (LC/MS) as the analysis of intact proteins, carbohydrates, and various small molecules, including peptides.

CE-MS characterization of negatively charged alpha-, beta- and gamma-CD derivatives and their application to the separation of dipeptide and tripeptide enantiomers by CE.

Sulfated, sulfopropyl and carboxymethyl alpha-, beta- and gamma-CDs were characterized by CE-ESI-MS using an acidic BGE with anodic MS detection and a basic BGE with cathodic MS detection. Isomers of the sulfated CDs comigrated in both systems. The acidic BGE with anodic MS detection resulted in slightly better separation of the isomers of the sulfopropyl CDs, which were separated according to the number of substituents.

The selective determination of sulfates, sulfonates and phosphates in urine by CE-MS.

Metabolite identification and metabolite profiling are of major importance in the pharmaceutical and clinical context. However, highly polar and ionic substances are rarely included as analytical tools are missing. In this study, we present a new method for the determination of urinary sulfates, sulfonates, phosphates and other anions of strong acids.