Increasing the Robustness of SIFT-MS Volatilome Fingerprinting by Introducing Notional Analyte Concentrations

Selected ion flow tube-mass spectrometry (SIFT-MS) isan analyticaltechnique for volatile detection and quantification. SIFT-MS can beapplied in a white box approach, measuring concentrationsof target compounds, or as a black box fingerprintingtechnique, scanning all product ions during a full scan. CombiningSIFT-MS full scan data acquired from multibatches or large-scale experimentsremains problematic due to signal fluctuation over time. The standardapproach of normalizing full scan data to the total signal intensitywas insufficient. This study proposes a new approach to correct SIFT-MSfingerprinting data. In this concept, all of the product ions froma full scan are considered individual compounds for which notionalconcentrations can be calculated. Converting ion count rates intonotional analyte concentrations accounts for any changes in the instrumentparameters. The benefits of the proposed approach are demonstratedon three years of data from both multibatches and long-term experimentsshowing a significant reduction of system-induced fluctuations providinga better focus on the changes of interest.

Automated summary

Selected ion flow tube-mass spectrometry (SIFT-MS) is a technique for detecting and quantifying volatile compounds. It can be used to measure concentrations of target compounds or as a fingerprinting technique to scan all product ions. However, combining SIFT-MS full scan data from multiple batches or large-scale experiments is challenging due to signal fluctuation over time.