1. ABOUT THE DATASET ------------ Title: Dataset supporting 'The use of salts, buffers and surfactants in LAP-MALDI MS' Creator(s): Henriette Krenkel Organisation(s): University of Reading Rights-holder(s): University of Reading Publication Year: 2023 Description: As part of the PhD project 'Advancing liquid MALDI ion source designs and applications in modern biological mass spectrometry' funded by the University of Reading and Waters Corporation the influence of salts, buffers, surfactants and other substances on the LAP-MALDI MS signal of a peptide mix was investigated. The peptide mix containing leucine enkephalin, angiotensin I, bradykinin, substance P and melittin was mixed with substances at different concentrations. Those were: 1) buffers (HEPES, MES, MOPS, tris, tricine, PBS), 2) salts (chlorides of calcium, potassium, magnesium, sodium, ammonium and acetates of magnesium, ammonium and sodium), 3) surfactants (sodium dodecyl sulphate, sodium deoxycholate, octyl-beta-D-glucopyranoside, CHAPS, amidosulfobetamine-14), 4) ammonium salts and serine (ammonium acetate, tartrate, citrate, phosphate, oxalate) and 5) other substances (EDTA, ammonium sulphate, urea, bovine serum albumin, formic acid, trifluoracetic acid and dimethyl sulfoxide). All samples were analysed at least in triplicate with a water-based sample as reference. For the LAP-MALDI analysis a CHCA-based liquid support matrix was used and samples were analysed on a Synapt G2-SI. The data archived here include the raw data and sample locations. Cite as: Krenkel, Henriette (2023): Dataset supporting 'The use of salts, buffers and surfactants in LAP-MALDI MS'. University of Reading. Dataset. https://doi.org/10.17864/1947.000464 Related publication: H. Krenkel, J. Brown, M. Morris, R. Cramer (2023) The use of salts, buffers and surfactants in LAP-MALDI MS. International Journal of Mass Spectrometry, 493. 117134. doi: https://doi.org/10.1016/j.ijms.2023.117134. Contributors: Jeffery Brown[1], Michael Morris[1]; Rainer Cramer[2] [1] Water Corporation [2] University of Reading Contact: Prof. Rainer Cramer, Department of Chemistry, University of Reading, Reading RG6 6DX, United Kingdom, Tel: 0118 378 4550, Email: r.k.cramer@reading.ac.uk 2. TERMS OF USE ----------------- Copyright 2023 University of Reading. This dataset is licensed under a Creative Commons Attribution 4.0 International Licence: https://creativecommons.org/licenses/by/4.0/. 3. PROJECT AND FUNDING INFORMATION ------------ Title: Advancing liquid MALDI ion source designs and applications in modern biological mass spectrometry Dates: 2018-2023 Funding organisation: University of Reading, Waters Corporation 4. CONTENTS ------------ File listing: buffer.7zip other.7zip salt-remediation.7zip salts.7zip surfactants.7zip The files are sorted by the type of additive used. Each folder contains a .raw folder with the raw data for each dataset, a folder with the sliced data xx-sliced (one file per sample) and a sample list (.csv) which includes information about which additive was used on which sample position (x and y coordinates). Surfactants.7zip additionally contains a .raw folder for the data acquired on the Waters sample plate and for high surfactant concentrations. For the latter, extracted mass spectra are included. Raw files are in a proprietary format which can be opened with the mass spectrometry vendor's software (MassLynx by Waters). All data files contain a _extern file with relevant instrument settings recorded. These can be opened in Notepad or a similar text editor. Mass spectra were saved as .txt and contain m/z and intensity. 5. METHODS -------------------------- The dataset contains data that was generated using a commercial mass spectrometer Synapt G2-Si HDMS (Waters) equipped with an in-house developed AP-MALDI ion source. Masslynx (ver. 4.2; Waters) software was used to collect and process the data. Further processing making use of SpecProc (see https://sourceforge.net/projects/specproc/) and SpecProc SampleList (see https://sourceforge.net/projects/specproc-samplelist/).