Infrared Irradiation in the Collision Cell of a Hybrid Tandem Quadrupole/Time-of-Flight Mass Spectrometer for Declustering and Cleaning of Nanoelectrosprayed Protein Complex Ions

• Published in: Analytical chemistry (Washington) 2010-12, Vol.82 (23), p.9878-9884
• Main Authors: El-Faramawy, Ayman, Guo, Yuzhu, Verkerk, Udo H, Thomson, Bruce A, Siu, K.W. Michael
• Format: Article
• Language: English
• Subjects: Alcohol Dehydrogenase - chemistry; Analytical chemistry; Avidin - chemistry; Chaperonin 60 - chemistry; Chemistry; Exact sciences and technology; Infrared Rays; Ions; Lasers; Mass spectrometry; Molecular weight; Nanotechnology; Proteins; Spectrometric and optical methods; Spectrometry, Mass, Electrospray Ionization - instrumentation; Spectrometry, Mass, Electrospray Ionization - methods; Tandem Mass Spectrometry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac102351m

Herein we report the performance of a hybrid quadrupole time-of-flight tandem mass spectrometer with an improved designed for coaxial infrared laser introduction for the characterization and dissociation of large protein complex ions and their aggregates formed under nanoelectrospray ionization. The major improvement from the original design (Raspopov, S. A.; El-Faramawy, A.; Thomson, B. A.; Siu, K. W. M. Anal. Chem. 2006, 78, 4572−4577) involves the use of a hollow silica waveguide and physical isolation of the infrared laser. Large model protein complex ions and their aggregates examined include alcohol dehydrogenase, avidin, GroEL, and others. Gentle heating of these complexes with the infrared laser facilitated declustering and resulted in better resolved mass spectral peaks and more accurate molecular-weight measurements.