A RAPID ACQUISITION AND EXTRACTION TOOL FOR PROCESSING OF DESI SCREENING APPLICATION DATA

Significance of the Topic

Direct analysis using desorption electrospray ionization (DESI) as a rapid screening tool addresses the growing demand for high-throughput workflows in analytical chemistry. By acquiring multiple samples in a single continuous run, this approach accelerates applications such as lipid profiling in blood products, drug library screening, and real-time reaction monitoring in bioprocesses.

Study Objectives and Overview

The primary goal of the study is to develop and demonstrate a software solution, the Chrom Splitter app, capable of automatically dividing a single DESI raw data file containing multiple sample spots into individual files per sample. This ensures compatibility with conventional processing platforms and preserves all spectral information for downstream analysis.

Methodology and Instrumentation

Samples were prepared on PTFE-coated slides with 1–2 µL analyte spots arranged as 44 single-line passes (11 spots per line). Data were acquired in one continuous run using:

• a standard quadrupole time-of-flight (QToF) mass spectrometer
• An ion mobility-enabled Q-ToF instrument
• A high-resolution multi-reflecting Q-ToF system (resolution >200 000 FWHM)

The Chrom Splitter app segments data based on total ion chromatogram (TIC), extracted ion chromatogram (XIC) for specified m/z windows, or summed ion counts of target masses. An optional smoothing algorithm compensates for signal fluctuations.

Main Results and Discussion

The Chrom Splitter app effectively identified and extracted chromatographic regions corresponding to individual sample spots, discarding inter-spot scans and reducing file size. Segmented files were successfully processed in multiple software environments:

• MassLynx for XIC visualization (example m/z 780.6 corresponding to PC 37:3, –2 ppm mass accuracy)
• Progenesis QI for statistical feature analysis
• UNIFI for library searching including collision cross section (CCS) data
• Skyline for targeted signal comparison
• DriftScope for retention of ion mobility drift time dimensions

This workflow maintained all collision cross section and fragmentation details, facilitating accurate comparative studies across diverse sample types and acquisition modes (conventional MS, high-resolution MS, HDMSE).

Benefits and Practical Application of the Method

The described approach:

• Eliminates manual file splitting and redundant scan handling
• Accelerates data throughput by consolidating acquisition and automated segmentation
• Ensures full compatibility with established data processing tools
• Supports high-throughput screening in pharmaceutical, clinical, and industrial laboratories

Future Trends and Potential Uses

Anticipated developments include integration of ambient ionization methods beyond DESI, real-time segmentation and feedback for reaction monitoring, cloud-based processing pipelines, and machine learning–driven feature detection to further enhance throughput and analytical depth.

Conclusion

The Chrom Splitter application provides a robust solution for processing continuous DESI screening data. By automating segmentation and retaining comprehensive spectral and ion mobility information, it streamlines workflows, reduces manual effort, and broadens compatibility with existing analysis platforms.

Reference

1. MacLean B et al Bioinformatics 2010