title: Simple correction improving long-term reproducibility of HPLC-MS.
abstract: Chromatographic peak areas in long series of high-performance liquid chromatography-MS experiments often vary, which decrease reproducibility and may cause bias in the results. It was found that the sensitivity of various components change differently; in our case, variability is in the order of 20-40%, and it is most likely due to changing conditions in electrospray ionization (ESI). The most often used peak area correction methods do not take this effect into account. The change in peak areas can be well described by a polynomial function; we found that a fourth-order polynomial is most often suitable. We suggest a simple correction algorithm based on polynomial fitting. When the experiments were inherently well reproducible, this correction improved reproducibility from 12% to 3% (on average for various components). When random errors were larger, this improvement was less significant (15% to 12% in nano-ESI) but nevertheless essential in order to avoid possible bias in the results.
authors.affiliation: MS Proteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.|School of Ph.D. Studies, Semmelweis University, Üllői út 26, H-1085, Budapest, Hungary.
authors.forename: Eszter
authors.initials: E
authors.lastname: Tóth
authors.affiliation: Gedeon Richter PLC, H-1475, Budapest, PO Box 27, Hungary.|Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4., H-1111, Budapest, Hungary.
authors.forename: Helga
authors.initials: H
authors.lastname: Hevér
authors.affiliation: MS Proteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.|MTA-TTK NAP B MS Neuroproteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.
authors.forename: Olivér
authors.initials: O
authors.lastname: Ozohanics
authors.affiliation: Department of Oncology, Bajcsy-Zsilinszky Municipal Hospital, Maglódi út 89, H-1106, Budapest, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Telekes
authors.affiliation: MS Proteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.|Core Technologies Centre, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.
authors.forename: Károly
authors.initials: K
authors.lastname: Vékey
authors.affiliation: MS Proteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.|MTA-TTK NAP B MS Neuroproteomics Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H-1519, Budapest, PO Box 286, Hungary.
authors.forename: László
authors.identifier: http://orcid.org/0000-0001-9589-6652
authors.initials: L
authors.lastname: Drahos
keywords: HPLC-MS; electrospray; long-term stability; proteomics; signal drift