Poster Presentations
Day 1, June 10（Wed.） Room P (5F 501+502)
- 1P-42
Impact of Narrow Q1 Isolation Windows on Identification Depth in ZT Scan DIA
(1AB SCIEX, 2SCIEX Canada)
oTakeshi Shibata1, Ushio Takeda1, Anjali Chelur2
The ZT Scan data independent acquisition (DIA) workflow on the Zeno TOF 8600 system allows flexible tuning of selectivity and sensitivity to accommodate chromatography, sample load, and matrix complexity. In this study, we evaluated the impact of Q1 isolation window width on identification depth and quantitative performance across a range of liquid chromatography (LC) conditions. Narrow Q1 isolation windows reduce precursor co-isolation and ion load entering the collision cell, thereby minimizing co-fragmentation and spectral complexity.
K562 digest samples at varying concentrations were analyzed using ZT Scan DIA with isolation windows from 1 to 5 Da under both nanoflow and microflow LC, spanning long to short gradients. Identification performance was assessed at 1% FDR using DIA NN, while quantitative precision was evaluated from replicate injections.
Narrow isolation windows consistently improved identification depth, particularly for short gradients and higher sample loads where spectral congestion is most pronounced. Despite narrower windows, fast acquisition rates preserved sufficient sampling density, maintaining robust quantitative precision with median CVs below 5%. For lower sample loads, wider isolation windows provided advantages due to increased ion accumulation.
These results establish practical guidelines for selecting Q1 isolation widths to optimize identification depth while preserving quantitative accuracy under diverse LC and sample conditions.