Paper Spray for Direct Analysis of Complex Mixtures Using Mass Spectrometry

Abstract

Complex mixtures can be ionized directly from paper for quantitative mass spectrometric analysis of trace components. Prior separations are an option.

Assessment of paper spray ionization for quantitation of pharmaceuticals in blood spots

“…It is likely that such suppression will occur, however, at very low concentrations of drug where the internal standard is several orders of magnitude more concentrated. Further experiments are needed to determine the linear dynamic range, although previous studies with paper spray indicate that the method is linear over at least three decades [5].…”

“…The chemotherapeutic drug imatinib, for example, was detected as low as 50 ng/mL from dried blood, well below the typical therapeutic value for this drug [18], and the analysis showed good linearity over the entire range examined (62.5 ng/mL to 4 g/mL) [5]. The paper spray method is also simple (it involves a single step), it can be performed on less than a microliter of blood, requires small amounts of organic solvent, and uses low cost and readily available materials.…”

“…Another recently described variant of electrospray ionization is paper spray ionization [5,6], in which samples are deposited onto paper; after application of solvent and a high voltage, analyte transport and ionization by the electrospray process is affected. Fenn himself touched on this idea over a decade ago when he filed for a patent for performing ESI through a wicking element [7], which he saw as a way to couple the different fluid flow regimes of ESI and HPLC.…”

A Low-Cost, Simplified Platform of Interchangeable, Ambient Ionization Sources for Rapid, Forensic Evidence Screening on Portable Mass Spectrometric Instrumentation

“…Analytes of interest can be investigated through a myriad of sampling strategies, such as deposition via pipetting, swabbing or dipping, and the swab itself can be used as a surface-transfer medium to investigate bound, trace residues [6,19]. Addition of a small aliquot (1-2 µL) of solution (e.g., 1:1 MeOH:H 2 O with 0.1% formic acid via pipette) and high voltage allows analyte dissolvation and wicking/elution to the triangular egress of the paper, from which an ESI-like spray is generated [48]. As there is no need for pneumatics or extensive sample preparation, it is one of the simplest techniques for coupling to portable MS systems.…”

Folding-paper-based preconcentrator for low dispersion of preconcentration plug

“…First, following standard FTA extraction protocol, we plan to apply preconcentrated samples for FTA R cards. Second, we could analyze the preconcentrated sample reservoir using paper-based mass spectrometry [26,27].…”