178
IRUS Total
Downloads

Identification and quantification of VOCs by Proton Transfer Reaction Time of Flight Mass Spectrometry: an experimental workflow for the optimization of specificity, sensitivity and accuracy

File Description SizeFormat 
Romano_et_al-2018-Journal_of_Mass_Spectrometry.pdfPublished version872.1 kBAdobe PDFView/Open
Title: Identification and quantification of VOCs by Proton Transfer Reaction Time of Flight Mass Spectrometry: an experimental workflow for the optimization of specificity, sensitivity and accuracy
Authors: Romano, A
Hanna, G
Item Type: Journal Article
Abstract: Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-ToF-MS) is a direct injection MS technique, allowing for the sensitive and real-time detection, identification and quantification of volatile organic compounds (VOCs). When aiming to employ PTR-ToF-MS for targeted VOC analysis some methodological questions must be addressed, such as the need to correctly identify product ions, or evaluating the quantitation accuracy. This work proposes a workflow for PTR-ToF-MS method development, addressing the main issues affecting the reliable identification and quantification of target compounds. We determined the fragmentation patterns of 13 selected compounds (aldehydes, fatty acids, phenols). Experiments were conducted under breath-relevant conditions (100% humid air), and within an extended range of reduced electric field values (E/N = 48-144 Td), obtained by changing drift tube voltage. Reactivity was inspected using H3O+, NO+ and O2+ as primary ions. The results show that a relatively low (< 90 Td) E/N often permits to reduce fragmentation enhancing sensitivity and identification capabilities, particularly in the case of aldehydes using NO+, where a 4-fold increase in sensitivity is obtained by means of drift voltage reduction. We developed a novel calibration methodology, relying on diffusion tubes used as gravimetric standards. For each of the tested compounds, it was possible to define suitable conditions whereby experimental error, defined as difference between gravimetric measurements and calculated concentrations, was 8% or lower.
Issue Date: 1-Apr-2018
Date of Acceptance: 5-Jan-2018
URI: http://hdl.handle.net/10044/1/56097
DOI: https://dx.doi.org/10.1002/jms.4063
ISSN: 1076-5174
Publisher: Wiley
Start Page: 287
End Page: 295
Journal / Book Title: Journal of Mass Spectrometry
Volume: 53
Issue: 4
Copyright Statement: © 2018 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any me dium, provided the original work is properly cited.
Sponsor/Funder: Medical Research Council (MRC)
Funder's Grant Number: MC_PC15028
Keywords: PTR-ToF-MS
breath analysis
ion chemistry
method development
volatile organic compounds
03 Chemical Sciences
Analytical Chemistry
Publication Status: Published
Online Publication Date: 2018-01-16
Appears in Collections:Department of Surgery and Cancer