Field-Switching Repeller Flowing Atmospheric-Pressure Afterglow Drift Tube Ion Mobility Spectrometry

Abstract

In this work, a field-switching (FS) technique is employed with a flowing atmospheric pressure afterglow (FAPA) source in drift tube ion mobility spectrometry (DTIMS). The premise is to incorporate a tip-repeller electrode as a substitute for the Bradbury−Nielsen gate (BNG) so as to overcome corresponding disadvantages of the BNG, including the gate depletion effect (GDE). The DTIMS spectra were optimized in terms of peak shape and full width by inserting an aperture at the DTIMS inlet that was used to control the neutral molecules' penetration into the separation region, thus preventing neutral-ion reactions inside. The FAPA and repeller's experimental operating conditions including drift and plasma gas flow rates, pulse injection times, repeller positioning and voltage, FAPA current, and effluent angle were optimized. Ion mobility spectra of selected compounds were captured, and the corresponding reduced mobility values were calculated and compared with the literature. The 6-fold improvements in limit of detection (LOD) compared with previous work were obtained for 2,6-DTBP and acetaminophen. The enhanced performance of the FS-FAPA-DTIMS was also investigated as a function of the GDE when compared with FAPA-DTIMS containing BNG.

RETRACTED: Anti-inflammatory effect of functionalized sulfasalazine boron nitride nanocages on cardiovascular disease and breast cancer: An in-silico simulation

“…In contrast to carbon nanostructures which are made up of covalent bonded carbon atoms, BN nanostructures are ionic bonded comprising of negatively charged N and positively charged B atoms. The bonded boron and nitrogen atoms have empty p orbitals and lone pair electrons respectively which provide additional covalent interactions with external molecules [110]. Owing to their ionic and covalent characters, these structures tend to offer a unique set of physisorption and chemisorption properties for various external molecules as compared with carbon nanostructures [109].…”