TY - JOUR
T1 - Enhancing performance of liquid sample desorption electrospray ionization mass spectrometry using trap and capillary columns
AU - Cheng, Si
AU - Wang, Jun
AU - Cai, Yi
AU - Loo, Joseph A.
AU - Chen, Hao
N1 - Funding Information:
This work was supported by NSF Career Award ( CHE-1149367 ), NSF ( CHE-1455554 ), and NNSFC ( 21328502 ). JAL acknowledges support from the National Institutes of Health ( R01GM103479 ).
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/12/3
Y1 - 2015/12/3
N2 - Desorption electrospray ionization mass spectrometry (DESI-MS) is a recent and important advance in the field that has extensive applications in surface analysis of solid samples but has also been extended to analysis of liquid samples. The liquid sample DESI typically employs a piece of fused silica capillary to transfer liquid sample for ionization. In this study, we present the improvement of liquid sample DESI-MS by replacing the sample transfer silica capillary with a trap column filled with chromatographic stationary phase materials (e.g., C4, C18). This type of trap column/liquid sample DESI can be used for trace analysis of organics and biomolecules such as proteins/peptides (in nM concentration) in high salt content matrices. Furthermore, when the sample transfer capillary is modified with enzyme covalently bound on its inside capillary wall, fast digestion (<6 min) of proteins such as phosphoproteins can be achieved and the online digested proteins can be directly ionized using DESI with high sensitivity. The latter is ascribed to the freedom to select favorable spray solvent for the DESI analysis. Our data show that liquid sample DESI-MS with a modified sample transfer capillary has significantly expanded utility in bioanalysis.
AB - Desorption electrospray ionization mass spectrometry (DESI-MS) is a recent and important advance in the field that has extensive applications in surface analysis of solid samples but has also been extended to analysis of liquid samples. The liquid sample DESI typically employs a piece of fused silica capillary to transfer liquid sample for ionization. In this study, we present the improvement of liquid sample DESI-MS by replacing the sample transfer silica capillary with a trap column filled with chromatographic stationary phase materials (e.g., C4, C18). This type of trap column/liquid sample DESI can be used for trace analysis of organics and biomolecules such as proteins/peptides (in nM concentration) in high salt content matrices. Furthermore, when the sample transfer capillary is modified with enzyme covalently bound on its inside capillary wall, fast digestion (<6 min) of proteins such as phosphoproteins can be achieved and the online digested proteins can be directly ionized using DESI with high sensitivity. The latter is ascribed to the freedom to select favorable spray solvent for the DESI analysis. Our data show that liquid sample DESI-MS with a modified sample transfer capillary has significantly expanded utility in bioanalysis.
KW - Desalting and enrichment
KW - Desorption electrospray ionization
KW - Mass spectrometry
KW - Online enzyme digestion
KW - Phosphoprotein
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U2 - 10.1016/j.ijms.2015.09.010
DO - 10.1016/j.ijms.2015.09.010
M3 - Article
AN - SCOPUS:84947442059
SN - 1387-3806
VL - 392
SP - 73
EP - 79
JO - International Journal of Mass Spectrometry and Ion Processes
JF - International Journal of Mass Spectrometry and Ion Processes
ER -