Combination Atmospheric Pressure Solids Analysis Probe and Desorption Electrospray Ionization Mass Spectrometry Ion Source

Abstract

The atmospheric solids probe analysis (ASAP) probe was investigated as a means for conducting desorption electrospray ionization (DESI) using a commercially available ion source. Solid and liquid samples as well as a raw urine sample were placed on individual melting point tubes and were inserted into either a heated gas stream for ASAP analysis or a charged solvent spray for DESI-like experiments. Samples ranged in polarity, volatility, mass, (100-17,000 Da), and concentration (neat to submicromolar). Mass spectra of multiple samples were obtained within a single acquisition on a short time scale (<30 s per sample). The configuration of the ion source also allowed rapid switching (approximately 1 min) between ASAP, electrospray ionization (ESI), and DESI.

Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

“…24,25 In this case only negative ions, M − , were recorded in an appropriate mass range at 70 000 mass resolution. The APCI probe was used without a flow of solvent, although a solution of reserpine was introduced through the APCI probe during the experiments to serve as a lock mass in negative ion mode.…”

Laserspray ionization using an atmospheric solids analysis probe for sample introduction

“…The full range (m/z 400 -2000) mass spectra of all compounds were obtained in Ͻ1 min and carryover between samples was not observed. Adduct ions were not observed for either the peptides or proteins and the LSI method produced improved spectral appearance relative to the ASAP/DESI-like method [16]. Based on ion abundances, at the concentrations used, it should be possible with faster sample movement to obtain excellent mass spectra for each sample within only a few seconds of acquisition.…”

“…The ASAP method is applied to analysis of volatile and semivolatile materials, but was recently shown to be applicable to nonvolatile compounds by using a commercial ESI probe to produce ions of peptides, proteins, and other compounds deposited on the melting point tube by a desorption electrospray ionization (DESI)-like method [16]. The DESI-like configuration required precise alignment of the ESI probe with respect to a melting point tube held in place directly in front of the mass spectrometer (MS) ion entrance orifice by the ASAP assembly.…”

High‐throughput analysis of peptides and proteins by laserspray ionization mass spectrometry

“…AP-MALDI-MS is an option for eliminating these drawbacks, but itself is limited by the mass limitation of the analyzer (typically <4000 Da). Fast ambient analyses [5][6][7][8][9][10][11] have the potential to be immensely useful as they eliminate most sample preparation procedures and operate at AP.…”