Design and performance of an in-line surface-induced dissociation device in a four-sector mass spectrometer

Abstract

A new in-line surface-induced dissociation device has been designed and characterized in a high performance four-sector tandem mass spectrometer. The design incorporates a target electrode parallel to the ion beam axis and an angled deflector plate (45° relative to the ion beam) to provide large collision angles. In addition, an extraction electrode (parallel to the target electrode) is employed to efficiently extract product ions from the target surface. Results obtained with this device indicate high internal energy deposition (up to 16. 3 eV) as measured with the thermometer ions W(CO) 6 (+·) and Si(C2H5)4/+·, as evidenced by extensive dissociation of the refractory pyrene molecular ion, and as indicated by the b 3/y 2 ratio in the product ion spectrum of leucine enkephalin. High resolution provided by the four-sector instrument for both precursor ions and product ions allows the observation of previously unobserved dissociation products in the surface-induced dissociation spectra of Si(C2H5)4/+· and novel ion-surface reaction products in spectra of W(CO)6/+· ions after collisions with hydrocarbon-covered surfaces. Both hydrogen atom and hydrocarbon abstraction products are observed. The dissociation efficiencies measured with the in-line device are approximately 1% when hydrocarbon-coated surfaces are used and increase fivefold with a fluorinated surface.

Collisions of ions with surfaces at chemically relevant energies: Instrumentation and phenomena

“…Such devices have been used with tandem quadrupole instruments, 131,170,171 and with a tandem sector mass spectrometer. 172 This latter, a foursector instrument, yields SID data similar to that provided by other SID instruments with respect to internal energy deposition, however, it possesses the inherent advantage of superior mass resolution. The four-sector design also allows for rapid conversion between conventional collision-activated dissociation and dissociation due to surface collisions.…”

“…The four-sector design also allows for rapid conversion between conventional collision-activated dissociation and dissociation due to surface collisions. 172 An- ͑5͒ flight tube; ͑6͒ gate valve; ͑7͒ Einzel lens; ͑8͒ 12°deflector for neutrals elimination; ͑9͒ x,y deflector; ͑10͒ deceleration and focusing lenses; ͑11͒ quadrupole mass spectrometer; ͑12͒ ultraviolet source; ͑13͒ 180°hemispherical energy analyzer; ͑14͒ Auger electron gun; and ͑15͒ viewport. Reprinted with permission from Ref.…”

A beam scattering instrument for the dynamics studies of surface-induced dissociation processes

“…23,24 An alternative arrangement by Cooks et al 25 included two quadrupoles in parallel with an electrostatic quad to bend the ion beam by 90°prior to colliding with a surface. Other SID instruments include sector instruments modified for in-beam surface, 26 hybrid instruments such as sector and quadrupole, 27 or time-of-flight instruments, 28,29 reflectron or tandem time-of-flight mass spectrometers, 30,31 triple quadrupoles, 14 and Fourier transform ion cyclotron resonance mass spectrometers. 32,33 However, all these instruments did not provide information on the scattering of the fragment ions which is one of the most important parameter in understanding any collision process.…”

Translational to Vibrational Energy Conversion during Surface-Induced Dissociation of N-Butylbenzene Molecular Ions Colliding at Self-Assembled Monolayer Surfaces

“…12 Subsequently, more quantitative data in regard to energy transfer efficiency have been sought using ions that dissociate by linear sequences of fragmenta-tions with well-known energy requirements, namely thermometer ions. 13,14 The molecular ions of transition metal carbonyls have long been used in such applications, [15][16][17][18][19][20][21][22] ever since the consecutive fragmentation reactions of Cr(CO) 6 + were studied by threshold photoelectron photoion coincident (TPEPICO) time-of-flight mass spectrometry. 23 Since these reactions are assumed to have virtually no kinetic shift, these kinetically well-defined systems can be used directly to estimate internal energies from idealized breakdown curves.…”