Rapid analysis of peptides and amino acids by CE‐ESI‐MS using chemically modified fused‐silica capillaries

Abstract

The objective of this study was to prepare a coated capillary to achieve rapid analysis of peptides and amino acids (AAs) by CE-ESI-MS. The coated capillary was prepared by chemical modification of the fused silica (FS) capillary with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) via a silanization reaction followed by an on-column in situ graft polymerization. In preparing capillary coating, AMPS was introduced for the following two purposes: first, to achieve strong and stable EOF in a wide pH range, and second, to obtain good repeatability of separations of peptides and AAs by reducing their adsorption to the FS capillary. The inner wall morphology, the characteristics of EOF, and the performances of coated capillary including separation ability, repeatability, and stability were investigated in detail and evaluated by analyses of four peptides (D-Ala-D-Ala, Gly-Gly-L-Leu, Gly-D-Phe, and L-Leu-D-Leu) and three AAs (glycine, glutamic acid, and phenylalanine), respectively. Under the optimized conditions, the analysis times of four peptides and three AAs in the coated capillary were 5.6 and 6.0 min, respectively, i.e. much shorter than those in the bare-FS capillary, 20 and 26 min, respectively. These coated capillaries were shown to be well suitable for CE coupling with ESI-MS to analyze peptides and AAs thanks to high separation power, short analysis times, good repeatability and high stability.

Improved separation and detection of picolinic acid and quinolinic acid by capillary electrophoresis-mass spectrometry: Application to analysis of human cerebrospinal fluid

“…To improve the variability of migration times and peak areas as well as to prevent capillary tip erosion in CE-MS with a BFS capillary, the use of chemically modified covalently coated capillary is a promising approach [23,24]. The repeatability of the CE-ESI-MS/MS method with the VBTA coated capillary (Fig.…”

“…The use of covalently coated capillaries is a promising approach to minimize the variability of migration time and peak area on bare fused-silica (BFS) capillary in CE and CE-MS [23,24]. In this article, we focused on the development of CE-electrospray ionization (ESI)-MS/MS method for simultaneous separation and quantitation of the PA and QA in human CSF.…”

Poly(N‐vinylimidazole)‐grafted capillary for electrophoresis prepared by surface‐initiated atom transfer radical polymerization

“…The EOF increased from −2.8×10 −8 (m 2 /V·s) at pH 3.0 to 1.1×10 −8 (m 2 /V·s) at pH 9.0, which was fivefold lower than that of the uncoated capillary under the same condition. The flow rate of EOF is mainly ascribed to the charge density of all the charged groups on the capillary wall 37. In this PVI‐modified capillary, they are amine groups of the BTPAm, imidazole groups and the residual silanol groups on the capillary inner surface.…”

Recent developments in CE and CEC of peptides (2009–2011)

“…Covalent capillary coating with a 2‐acrylamido‐2‐methyl‐1‐propansulfonic acid via a silanization reaction followed by an on‐column in situ graft was shown to be suitable for fast CE‐ESI‐MS analysis of peptides and amino acids 89. Novel covalently coated capillaries were prepared by modification of their activated inner walls by derivatized polystyrene nanoparticles or fullerenes.…”