Description

This 3-D printable device allows for the interfacing of Faradaic ion concentration polarization to Paper Spray Ionization - Mass Spectrometry, allowing for a one to two order of magnitude increase in signal, due to a preconcentrating and desalting effect, as described by Rydberg, et al., in his Angewandte Chemie publication, "Paper Spray Mass Spectrometry with On‐Paper Electrokinetic Manipulations: Part‐Per‐Trillion Detection of Per/Polyfluoroalkyl Substances in Water and Opioids in Urine" (2024). Specifically, the apparatus electrokinetically migrates disperse analyte (such as toxicological samples or other) into a concentrated band on the paper, which can then be sampled all at once, into the inlet. A rear well is present for the loading of background electrolyte (BGE), with paper to be positioned from that well upward, with an additional paper positioned in the front well, sans BGE. The second (smaller) part of the apparatus is then fitted onto the first, with both aforementioned paper substrates interfacing with the final substrate, positioned within the smaller part. A Pt cathode is positioned in the rear well, and a Pt anode is positioned to cross the lower front paper substrate, through the holes in the apparatus designed to hold the appropriate wires. ~250 - 350 V are applied, external to the MS. An additional wire interfaces with the apparatus from the MS ionization source, applying ~4 kV spray voltage. For additional chemical and setup information, see the aforementioned publication.