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Quantitative determination of acetylcholine in microdialysis samples using liquid chromatography/atmospheric pressure spray ionization mass spectrometry
Author(s) -
KeskiRahkonen Pekka,
Lehtonen Marko,
Ihalainen Jouni,
Sarajärvi Timo,
Auriola Seppo
Publication year - 2007
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3162
Subject(s) - chemistry , atmospheric pressure chemical ionization , chromatography , mass spectrometry , electrospray ionization , analytical chemistry (journal) , microdialysis , high performance liquid chromatography , analyte , chemical ionization , direct electron ionization liquid chromatography–mass spectrometry interface , detection limit , ionization , ion trap , ion , biochemistry , extracellular , organic chemistry
Abstract A fast, simple and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of acetylcholine in rat brain microdialysis samples. The chromatographic separation was achieved in 3 min on a reversed‐phase column with isocratic conditions using a mobile phase containing 2% (v/v) of acetonitrile and 0.05% (v/v) of trifluoroacetic acid (TFA). A stable isotope‐labeled internal standard was included in the analysis and detection was carried out with a linear ion trap mass spectrometer using selected reaction monitoring (SRM). Analyte ionization was performed with an atmospheric pressure chemical ionization (APCI) source without applying discharge current (atmospheric pressure spray ionization). This special ionization technique offered significant advantages over electrospray ionization for the analysis of acetylcholine with reversed‐phase ion‐pairing chromatography. The lower limit of quantification was 0.15 nM (1.5 fmol on‐column) and linearity was maintained over the range of 0.15–73 nM, providing a concentration range that is significantly wider than that of the existing LC/MS methods. Good accuracy and precision were obtained for concentrations within the standard curve range. The method was validated and has been used extensively for the determination of acetylcholine in rat brain microdialysis samples. Copyright © 2007 John Wiley & Sons, Ltd.