Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.analchem.1c02348
Title (Primary) Development and application of liquid chromatographic retention time indices in HRMS-based suspect and nontarget screening
Author Aalizadeh, R.; Alygizakis, N.A.; Schymanski, E.L.; Krauss, M.; Schulze, T. ORCID logo ; Ibáñez, M.; McEachran, A.D.; Chao, A.; Williams, A.J.; Gago-Ferrero, P.; Covaci, A.; Moschet, C.; Young, T.M.; Hollender, J.; Slobodnik, J.; Thomaidis, N.S.
Journal Analytical Chemistry
Year 2021
Department WANA
Volume 93
Issue 33
Page From 11601
Page To 11611
Language englisch
Topic T9 Healthy Planet
Abstract There is an increasing need for comparable and harmonized retention times (tR) in liquid chromatography (LC) among different laboratories, to provide supplementary evidence for the identity of compounds in high-resolution mass spectrometry (HRMS)-based suspect and nontarget screening investigations. In this study, a rigorously tested, flexible, and less system-dependent unified retention time index (RTI) approach for LC is presented, based on the calibration of the elution pattern. Two sets of 18 calibrants were selected for each of ESI+ and ESI-based on the maximum overlap with the retention times and chemical similarity indices from a total set of 2123 compounds. The resulting calibration set, with RTI set to range between 1 and 1000, was proposed as the most appropriate RTI system after rigorous evaluation, coordinated by the NORMAN network. The validation of the proposed RTI system was done externally on different instrumentation and LC conditions. The RTI can also be used to check the reproducibility and quality of LC conditions. Two quantitative structure–retention relationship (QSRR)-based models were built based on the developed RTI systems, which assist in the removal of false-positive annotations. The applicability domains of the QSRR models allowed completing the identification process with higher confidence for substances within the domain, while indicating those substances for which results should be treated with caution. The proposed RTI system was used to improve confidence in suspect and nontarget screening and increase the comparability between laboratories as demonstrated for two examples. All RTI-related calculations can be performed online at
Persistent UFZ Identifier
Aalizadeh, R., Alygizakis, N.A., Schymanski, E.L., Krauss, M., Schulze, T., Ibáñez, M., McEachran, A.D., Chao, A., Williams, A.J., Gago-Ferrero, P., Covaci, A., Moschet, C., Young, T.M., Hollender, J., Slobodnik, J., Thomaidis, N.S. (2021):
Development and application of liquid chromatographic retention time indices in HRMS-based suspect and nontarget screening
Anal. Chem. 93 (33), 11601 - 11611