title: PCI-GC-MS-MS approach for identification of non-amino organic acid and amino acid profiles.
abstract: Alkyl chloroformate have been wildly used for the fast derivatization of metabolites with amino and/or carboxyl groups, coupling of powerful separation and detection systems, such as GC-MS, which allows the comprehensive analysis of non-amino organic acids and amino acids. The reagents involving n-alkyl chloroformate and n-alcohol are generally employed for providing symmetric labeling terminal alkyl chain with the same length. Here, we developed an asymmetric labeling strategy and positive chemical ionization gas chromatography-tandem mass spectrometry (PCI-GC-MS-MS) approach for determination of non-amino organic acids and amino acids, as well as the short chain fatty acids. Carboxylic and amino groups could be selectively labelled by propyl and ethyl groups, respectively. The specific neutral loss of C3H8O (60Da), C3H5O2(74Da) and C4H8O2(88Da) were useful in the selective identification for qualitative analysis of organic acids and amino acid derivatives. PCI-GC-MS-MS using multiple reaction monitoring (MRM) was applied for semi-quantification of typical non-amino organic acids and amino acids. This method exhibited a wide range of linear range, good regression coefficient (R2) and repeatability. The relative standard deviation (RSD) of targeted metabolites showed excellent intra- and inter-day precision (<5%). Our method provided a qualitative and semi-quantitative PCI-GC-MS-MS, coupled with alkyl chloroformate derivatization.
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
authors.forename: Hemi
authors.initials: H
authors.lastname: Luan
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
authors.forename: Fenfen
authors.initials: F
authors.lastname: Ji
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. Electronic address: zwcai@hkbu.edu.hk.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
mesh_terms: D000478:Alkylation; D000596:Amino Acids / Q000032:analysis*; D002264:Carboxylic Acids / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis*; D005243:Feces / Q000737:chemistry; D005561:Formates / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D005227:Fatty Acids; D005561:Formates; C083354:chlorocarbonic acid
keywords: Alkyl chloroformate; Amino acids; Derivatization; Non-amino organic acids; PCI-GC–MS–MS