European Journal of Mass Spectrometry - Abstract of Manipulation of charge states of biopolymer ions by atmospheric pressure ion/molecule reactions implemented in an extractive electrospray ionization source

Huanwen Chen,^a,b,d David Touboul,^d Matthias Conradin Jecklin,^d Jian Zheng,^b,c Mingbiao Luo^a,b and Renato Zenobi^d,*
^aApplied Chemistry Department, East China Institute of Technology, Fuzhou, China
^bChemistry College, Jilin University, Changchun, China
^cBeijing Academy of Science and Technology, 27 Northern Road, West Sanhuan, Beijing, China
^dChemistry Department and Applied Biosciences, ETH Zürich, HCI E 329, CH-8093 Zürich, Switzerland. E-mail: zenobi@org.chem.ethz.ch

A home-made extractive electrospray ionization source is coupled to an linear quadrupole ion trap mass spectrometer to investigate ion/molecule reactions of biopolymers at ambient pressure. Multiply charged biopolymers such as peptides and proteins generated in an electrospray are easily reduced to a low charge state by the atmospheric pressure ion/molecule reactions occurring between the multiply charged ions and a strong basic reagent sprayed in neutral form into the electrospray plume. The charge state of the biopolymer ions can be manipulated by controlling the amount of the basic reagent. The production of biopolymer ions with low charge states results in a substantial improvement of sensitivity and reduced spectral congestion in ESI-MS. This is of importance for biopolymer mixture analysis and could have promising applications in proteomics.