Correction of Preprocessed MS Data R package mpactr version 0.3.3 An 'R' implementation of the 'python' program Metabolomics Peak Analysis Computational Tool ('MPACT') (Robert M. Samples, Sara P. Puckett, and Marcy J. Balunas (2023) <doi:10.1021/acs.analchem.2c04632>). Filters in the package serve to address common errors in tandem mass spectrometry preprocessing, including: (1) isotopic patterns that are incorrectly split during preprocessing, (2) features present in solvent blanks due to carryover between samples, (3) features whose abundance is greater than user-defined abundance threshold in a specific group of samples, for example media blanks, (4) ions that are inconsistent between technical replicates, and (5) in-source fragment ions created during ionization before fragmentation in the tandem mass spectrometry workflow. Software Depends: R (>= 3.5.0) Imports: cli, data.table, ggplot2, R6, Rcpp, stats, treemapify, viridis LinkingTo: Rcpp Suggests: knitr, rmarkdown, testthat (>= 3.0.0), tidyverse, plotly, Hmisc, corrplot, ggdendro, ggtext Patrick Schloss <pschloss@umich.edu> Comprehensive R Archive Network (CRAN) Allison Mason [aut] (ORCID: <https://orcid.org/0000-0003-1339-1592>), Gregory Johnson [aut] (ORCID: <https://orcid.org/0009-0008-3890-0297>), Patrick Schloss [aut, cre, cph] (ORCID: <https://orcid.org/0000-0002-6935-4275>) GPL (>= 3) 2026-05-21 application/tgz https://CRAN.R-project.org/package=mpactr doi:10.32614/CRAN.package.mpactr