The dataset includes raw data, processing files, and a pdf of processed spectra for the 1H, 13C, 31P and 19F NMR spectra, together with scanned copies of HRMS as pdf files, corresponding to the relevant characterisation data for compounds reported in "Simultaneous and sensitive quantification of protein and low molecular weight persulfides, polysulfides and H2S in biological samples" published in Nature Communications, accepted 2025. Compounds were prepared by Dr Alexander H. Harkiss, Dr Stefan Warrington and Dr Stuart T. Caldwell in the laboratory of Prof. Richard C. Hartley, University of Glasgow.  There is a pdf of all processed NMR spectra compiled together. All raw NMR data and processing files are included in folders labelled with the compound names used in the paper.  The 1H NMR data were acquired on Bruker AVIII 400 and AVIII 500 spectrometers and processed using Bruker Topspin software. The scanned copies of the HRMS are labelled with the compound names used in the paper. The HRMS were acquired using a Bruker MicroTOFq High Resolution Mass Spectrometer coupled to a time-of-flight (TOF) analyser for positive mode electrospray or an Agilent 6546 Q-TOF-MS High Resolution Accurate Mass Spectrometer.