Ren X, Liu J, Zhang C, Sun J, Luo H. Signal enhancement of carboxylic acids by inclusion with β-cyclodextrin in negative high-voltage-assisted laser desorption ionization mass spectrometry.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014;
28:115-122. [PMID:
24285396 DOI:
10.1002/rcm.6767]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 10/09/2013] [Accepted: 10/15/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE
It is difficult to directly analyze carboxylic acids in complex mixtures by ambient high-voltage-assisted laser desorption ionization mass spectrometry (HALDI-MS) in negative ion mode due to the low ionization efficiency of carboxylic acids.
METHODS
A method for the rapid detection of carboxylic acids in negative HALDI-MS has been developed based on their inclusion with β-cyclodextrin (β-CD).
RESULTS
The negative HALDI-MS signal-to-noise ratios (S/Ns) of aliphatic, aromatic and hetero atom-containing carboxylic acids can all be significantly improved by forming 1:1 complexes with β-CD. These complexes are mainly formed by specific inclusion interactions which are verified by their collision-induced dissociation behaviors in comparison with that of their corresponding maltoheptaose complexes. A HALDI-MS/MS method has been successfully developed for the detection of α-lipoic acid in complex cosmetics and ibuprofen in a viscous drug suspension.
CONCLUSIONS
The negative HALDI-MS S/Ns of carboxylic acids can be improved up to 30 times via forming non-covalent complexes with β-CD. The developed method shows the advantages of being rapid and simple, and is promising for rapid detection of active ingredients in complex samples or fast screening of drugs and cosmetics.
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