2 research outputs found
Pushing the Resolving Power of Tyndall–Powell Gate Ion Mobility Spectrometry over 100 with No Sensitivity Loss for Multiple Ion Species
Ion
gate is a key buildup for drift tube ion mobility spectrometry
(IMS) and its combination with mass spectrometry. Bradbury–Nielsen
gate, as the most commonly used ion gate in IMS, possesses a distinct
ion mobility discrimination effect due to its depletion features.
This impedes the scaling of the ion gate opening time to improve the
separation capability of IMS while keeping its sensitivity for multiple
ion species. In this work, a Tyndall–Powell gate (TPG) simply
composed of two identical wire grids was used to develop an ion gate
with nearly no ion mobility discrimination for IMS. Experimental results
showed that the TPG features a gate region where the electric field
for opening the gate could be enhanced to effectively solve the ion
mobility discrimination problem related to it. Meanwhile, enhancing
that electric field enabled the TPG-IMS to keep a resolving power
over 106 at 100 °C for ion peak with a signal-to-noise ratio
up to 800. With that TPG-IMS, baseline separation of two ion peaks,
the hydronium and the acetone monomer peaks with a reduced mobility
difference of only 0.04 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup>, was achieved with no sensitivity loss for the least
mobile acetone dimer ions
La pobreza en la prensa : palabras clave en los diarios de Argentina, Brasil, Colombia y México
Como podrá advertir el lector, la presente publicación se ha construido desde campos del conocimiento muy diversos y ha constituido un intento de poner en diálogo distintas perspectivas teóricas para dar cuenta de las palabras y las nociones con las que se conceptualiza la pobreza en la prensa de cuatro importantes países latinoamericanos. La heterogeneidad en los enfoques y los modos de tratamiento de la problemática constituye, desde nuestra perspectiva, una de las principales fortalezas de este trabajo. Consideramos que la complejidad de los fenómenos que abordamos requiere de aproximaciones que eviten simplificaciones y reduccionismos y den cuenta de los debates ideológicos y epistemológicos en torno a lo que constituye el problema más relevante en nuestros países