Abstract
In this study, ultraviolet (UV) laser desorption and vacuum UV single-photon (VUV SP) postionization were performed to ionize and successfully analyze 20 common amino acids. The analytical merit and efficiency of the ionization was compared with those of conventional UV matrix-assisted laser desorption ionization (UV-MALDI). A VUV light source (118 nm) was generated from the ninth harmonic of a Q-switched Nd:YAG laser, and the photon number was determined to be larger than 1012 for each laser pulse in the ionization region. In general, the detection sensitivity of VUV-SP-postionization was 10–100 times higher than that of conventional UV-MALDI. In particular, the ion signal from VUV-SP-postionization was considerably larger than that from UV-MALDI for analytes with low proton affinity such as glycine. However, some fragmentation of intact ions was observed in VUV-SP-postionization. Quantitative analysis performed using a glycine/histidine mixture and tryptophan/phenylalanine mixture revealed that the dynamic range of VUV-SP-postionization was one order of magnitude larger than that of UV-MALDI, indicating that VUV-SP-postionization is suitable for the quantitative analysis of amino acids.
Highlights
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, introduced in the late1980s by Hillenkamp et al [1,2], has been widely used in the characterization of biomolecules
Quantitative analysis performed using a glycine/histidine mixture and tryptophan/phenylalanine mixture revealed that the dynamic range of VUV-SP-postionization was one order of magnitude larger than that of UV-MALDI, indicating that
(2,5-DHB), α-cyano-4-hydroxycinnamic acid (CHCA), and sinapic acid (SA) are suitable for the analysis of peptides and proteins [19,20,21]. 2,5-DHB is suitable for the analysis of carbohydrates and lipids [22,23]
Summary
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, introduced in the late. A VUV source with a short wavelength (118 nm, 10.5 eV) can be obtained using the ninth harmonic generation by focusing the third harmonic (355 nm) of Nd:YAG into a xenon cell [50,51] This source is used extensively because of its suitable photon energy and short pulse duration (~5 ns), which is appropriate for TOF-MS. Compared with other nonlinear optical generation schemes, which have complicated experimental configurations, ninth harmonic generation from a Nd:YAG laser provides a convenient, low-cost, and compact VUV source for SP ionization in a mass spectrometer. The measurement indicated that the dynamic range of VUV-SP-postionization is larger than that of UV-MALDI by one order of magnitude This technique provides a powerful ionization platform for further applications
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
