Program

Poster Presentations

Day 2, June 11（Thu.）　　Room P (5F 501+502)

2P-20

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Evaluation of Ion-Droplet Separation Characteristics in Conjugated Octupole–Quadrupole Ion Guide

(¹Hitachi, ²Hitachi High-Tech)
^oMotoki Date¹, Masuyuki Sugiyama¹, Hideki Hasegawa¹, Yuichiro Hashimoto²

In mass spectrometers (MS) using an atmospheric pressure ion source, ion transmission efficiency in the initial low-vacuum region is limited by high-velocity gas stream from the ion source. To address this issue, we have developed a conjugated octupole–quadrupole ion guide (8-4IG), which spatially separates ions from the gas stream and guides them to the next vacuum stage. In MS with electrospray ionization (ESI), solvent droplets enter the vacuum chamber with ions, causing noise and contamination. Although 8-4IG has been considered capable of separating ions from droplets, their transmission characteristics through 8-4IG remain uncharacterized. Therefore, we developed an evaluation system that measures ions and droplets passed through 8-4IG, confirming its performance. With the constructed measurement system, we confirmed that the 8‑4IG selectively extracts ions from the gas stream while permitting droplets to travel straight with the flow, thus preventing droplets ingress into subsequent vacuum stages.

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