DOI: 10.48758/ufz.16519
title: Laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI-FT-ICR MS) data of organic matter adsorbed to gold and titanium dioxide nanoparticles.

description: This dataset contains processed and quality-checked laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI-FT-ICR MS) data for dissolved organic matter (DOM) eco-coronas formed on gold (Au-NPs) and titanium dioxide (TiO₂-NPs, P25) nanoparticles. It uses Suwannee River Fulvic Acid (SRFA) as the DOM reference material and includes experimental variables such as nanoparticle type, nanoparticle and SRFA concentrations, SRFA:NP mass ratios, supernatant dissolved organic carbon (DOC), and estimated nanoparticle counts and bound-molecule concentrations per spot.

The LDI-FT-ICR MS data were acquired from air-dried spots of NP–SRFA pellet suspensions (and SRFA standards and pristine nanoparticle). Each sample was spotted in triplicate; the "measurement_name" column identifies the mixture and replicate. The sample code before the underscore indicates the mixture, and the number after the underscore indicates the analytical replicate:

"First letter" (NP concentration): "H" = high (stock), "M" = medium (1:50 dilution), L = low (1:50² dilution).
"Second letter" (SRFA concentration): "H" = high, "M" = medium, "L" = low (same dilution scheme).
"Number after underscore (_1, _2, _3)": analytical replicate (1, 2, or 3).
Examples: "P25-HH_1" is replicate 1 of TiO₂-NPs at high NP and high SRFA; "AuNP-MM_2" is replicate 2 of Au-NPs at medium NP and medium SRFA. "BLK_P25" and "BLK_AuNP" denote Pristine nanoparticle (no SRFA); "SRFA-H", "SRFA-M", "SRFA-L" denote SRFA-only standards at high, medium, and low concentration.

Molecular formulas were assigned in the m/z range 150–1000 with strict elemental and quality constraints. Relative intensities (RI) and delta relative intensity (δRI) were used to compare corona composition to the SRFA standard and to relate DOM composition to molecular descriptors. The dataset provides molecular-level insight into how nanoparticle type, concentration, and SRFA:NP ratio influence eco-corona formation and LDI detectability, supporting method optimization and environmental risk assessment for engineered nanomaterials.

The dataset supports the findings presented in the companion paper: Gad et al., "Advancing Surface Analysis of Organic Matter Corona on Nanoparticles via LDI-FT-ICR MS" (manuscript submitted).

The dataset includes the following files:

"NP_SRFA_Ratio_summary.clean_2026-02-06.csv" – Aggregated summary statistics per measurement (peak counts, assigned formulas, mass accuracy, intensity-weighted molecular descriptors, formula class counts and fractions). One row per measurement (each replicate has its own row). The "measurement_name" links to the formulas file and DOC file (via the sample code, e.g. P25-HH, AuNP-MM).
"NP_SRFA_Ratio_formulas.clean_2026-02-06.csv" – Complete molecular formulas table for all measurements (peak m/z, formula, elemental ratios, DBE, AImod, formula class, etc.). The "measurement_name" matches the summary file; use it to filter by mixture and replicate.
"NP_SRFA_Ratio_DOC_2026-02-06.csv" – DOC and mixture design: "Type2 (SRFA, P25, AuNP), "Samples" (e.g. P25-HH, AuNP-MM), NP and SRFA mass ratios, supernatant DOC (mg/L), number of NPs/µL, bound molecules (pmol/µL), and lower/upper dissolved molecule estimates. The "Samples2 column corresponds to the sample code in "measurement_name" (the part before the underscore and replicate number).
"Repository_file_definition_2022_03_20.csv" – Definitions of all columns used in the summary, formulas, and DOC files.