Amino acid analysis by capillary electrophoresis electrospray ionization mass spectrometry

Tomoyoshi Soga, David N. Neiger

Research output: Contribution to journalArticle

360 Citations (Scopus)

Abstract

A method for the determination of underivatized amino acids based on capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) is described. To analyze free amino acids simultaneously a low acidic pH condition was used to confer positive charge on whole amino acids. The choice of the electrolyte and its concentration influenced resolution and peak shape of the amino acids, and 1 M formic acid was selected as the optimal electrolyte. Meanwhile, the sheath liquid composition had a significant effect on sensitivity and the highest sensitivity was obtained when 5 mM ammonium acetate in 50% (v/v) methanol- water was used. Protonated amino acids were roughly separated by CE and selectively detected by a quadrupole mass spectrometer with a sheath flow electrospray ionization interface. Under the optimized conditions, 19 free amino acids normally found in proteins and several physiological amino acids were well determined in less than 17 min. The detection limits for basic amino acids were between 0.3 and 1.1 μmol/L and for acidic and low molecular weight amino acids were less than 6.0 μmol/L with pressure injection of 50 mbar for 3 s (3 nL) at a signal-to-noise ratio of 3. This method is simple, rapid, and selective compared with conventional techniques and could be readily applied to the analysis of free amino acids in soy sauce.

Original languageEnglish
Pages (from-to)1236-1241
Number of pages6
JournalAnalytical Chemistry
Volume72
Issue number6
DOIs
Publication statusPublished - 2000 Mar 15
Externally publishedYes

Fingerprint

Capillary electrophoresis
Electrospray ionization
Mass spectrometry
Amino Acids
formic acid
Electrolytes
Basic Amino Acids
Mass spectrometers
Methanol
Signal to noise ratio
Molecular weight
Water

ASJC Scopus subject areas

  • Analytical Chemistry

Cite this

Amino acid analysis by capillary electrophoresis electrospray ionization mass spectrometry. / Soga, Tomoyoshi; Neiger, David N.

In: Analytical Chemistry, Vol. 72, No. 6, 15.03.2000, p. 1236-1241.

Research output: Contribution to journalArticle

@article{ee44307ced704a27b3c4243cc9df60fb,
title = "Amino acid analysis by capillary electrophoresis electrospray ionization mass spectrometry",
abstract = "A method for the determination of underivatized amino acids based on capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) is described. To analyze free amino acids simultaneously a low acidic pH condition was used to confer positive charge on whole amino acids. The choice of the electrolyte and its concentration influenced resolution and peak shape of the amino acids, and 1 M formic acid was selected as the optimal electrolyte. Meanwhile, the sheath liquid composition had a significant effect on sensitivity and the highest sensitivity was obtained when 5 mM ammonium acetate in 50{\%} (v/v) methanol- water was used. Protonated amino acids were roughly separated by CE and selectively detected by a quadrupole mass spectrometer with a sheath flow electrospray ionization interface. Under the optimized conditions, 19 free amino acids normally found in proteins and several physiological amino acids were well determined in less than 17 min. The detection limits for basic amino acids were between 0.3 and 1.1 μmol/L and for acidic and low molecular weight amino acids were less than 6.0 μmol/L with pressure injection of 50 mbar for 3 s (3 nL) at a signal-to-noise ratio of 3. This method is simple, rapid, and selective compared with conventional techniques and could be readily applied to the analysis of free amino acids in soy sauce.",
author = "Tomoyoshi Soga and Neiger, {David N.}",
year = "2000",
month = "3",
day = "15",
doi = "10.1021/ac990976y",
language = "English",
volume = "72",
pages = "1236--1241",
journal = "Analytical Chemistry",
issn = "0003-2700",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - Amino acid analysis by capillary electrophoresis electrospray ionization mass spectrometry

AU - Soga, Tomoyoshi

AU - Neiger, David N.

PY - 2000/3/15

Y1 - 2000/3/15

N2 - A method for the determination of underivatized amino acids based on capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) is described. To analyze free amino acids simultaneously a low acidic pH condition was used to confer positive charge on whole amino acids. The choice of the electrolyte and its concentration influenced resolution and peak shape of the amino acids, and 1 M formic acid was selected as the optimal electrolyte. Meanwhile, the sheath liquid composition had a significant effect on sensitivity and the highest sensitivity was obtained when 5 mM ammonium acetate in 50% (v/v) methanol- water was used. Protonated amino acids were roughly separated by CE and selectively detected by a quadrupole mass spectrometer with a sheath flow electrospray ionization interface. Under the optimized conditions, 19 free amino acids normally found in proteins and several physiological amino acids were well determined in less than 17 min. The detection limits for basic amino acids were between 0.3 and 1.1 μmol/L and for acidic and low molecular weight amino acids were less than 6.0 μmol/L with pressure injection of 50 mbar for 3 s (3 nL) at a signal-to-noise ratio of 3. This method is simple, rapid, and selective compared with conventional techniques and could be readily applied to the analysis of free amino acids in soy sauce.

AB - A method for the determination of underivatized amino acids based on capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) is described. To analyze free amino acids simultaneously a low acidic pH condition was used to confer positive charge on whole amino acids. The choice of the electrolyte and its concentration influenced resolution and peak shape of the amino acids, and 1 M formic acid was selected as the optimal electrolyte. Meanwhile, the sheath liquid composition had a significant effect on sensitivity and the highest sensitivity was obtained when 5 mM ammonium acetate in 50% (v/v) methanol- water was used. Protonated amino acids were roughly separated by CE and selectively detected by a quadrupole mass spectrometer with a sheath flow electrospray ionization interface. Under the optimized conditions, 19 free amino acids normally found in proteins and several physiological amino acids were well determined in less than 17 min. The detection limits for basic amino acids were between 0.3 and 1.1 μmol/L and for acidic and low molecular weight amino acids were less than 6.0 μmol/L with pressure injection of 50 mbar for 3 s (3 nL) at a signal-to-noise ratio of 3. This method is simple, rapid, and selective compared with conventional techniques and could be readily applied to the analysis of free amino acids in soy sauce.

UR - http://www.scopus.com/inward/record.url?scp=0034654337&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034654337&partnerID=8YFLogxK

U2 - 10.1021/ac990976y

DO - 10.1021/ac990976y

M3 - Article

C2 - 10740865

AN - SCOPUS:0034654337

VL - 72

SP - 1236

EP - 1241

JO - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

IS - 6

ER -