This repository outlines the procedure for estimating PFAS concentrations from suspect and non-target high resolution mass spectrometry data. This procedure can be done using any statistical software that allows for weighted linear regressions. The author is unaware of an Excel add-in that performs this function. The author chose R for its free, open source capabilities and familiarity within the environmental chemistry field.
PFAScurve.Rmd is an R Markdown file with the code for generating a weighted least squares regression (i.e. weighted linear regression) from the Excel file "Calibration PFAS Curve.xlsx". The Excel file contains the LCMS calibration data from 50 PFAS analytes used to generate the "PFAS curve". The PFAS curve can be used to estimate concentrations for PFAS which have no authentic standard, sometimes called "suspects" or "nontargets".
Concept published by Cao & Schwichtenberg et al. 2023 (https://pubs.acs.org/doi/10.1021/jasms.3c00019)