Raw PTR-MS data to a spreadsheet.

Sniff reads IONICON IoniTOF PTR-MS and PTR-TOF .h5 files, including acquisition and calibration information present in the file.

It finds local maxima in the average mass spectrum above relative and robust noise thresholds, merges maxima within one instrument linewidth, and proposes candidates for review.

Sniff builds a composite VOC signal from strong m/z 40-200 traces and finds stable plateaus in log space. Elevated plateaus are proposed as samples and lower ones as backgrounds; short same-class gaps may be joined.

No. Sniff reads the raw file and writes the review configuration beside it; accepted results are exported to a CSV without modifying the .h5.

Sniff enumerates formula candidates offline and ranks them using exact-mass error, isotope patterns, chemical plausibility and optional library context. They remain candidates: structural isomers and overlapping signals can stay ambiguous, and scores are not probabilities. Names and isomer labels come from the bundled PTR Library mapping.

Background intervals are kept separate in the CSV and provide the baseline context for review and sample-vs-background checks. Review and correct the proposed classes before export because those labels affect the reported intervals.

Sniff transmission-corrects peak signals, normalises them by the primary-ion signal and applies K to report ppb and µg/m³, with optional measured kinetic corrections. K is not uniquely fixed by every raw file; use an appropriate calibration, and obtain an instrument-specific humidity calibration before treating humidity-sensitive compounds as absolute.

The sidecar JSON retains your peaks, intervals and analysis settings, plus validated mass-axis calibration evidence and a fingerprint of the source H5. The raw spectra remain in the H5 rather than being duplicated in the config.

Analysis and review run locally, and Sniff never uploads your measurement file. The app may check GitHub Releases for update metadata; if you explicitly configure an agent endpoint, review configuration and diagnostics are sent to that chosen service.

Yes. The macOS, Windows and Linux packages include the runtime and dependencies needed by the app. On Linux, use the .deb on Ubuntu 22.04+, Debian 12+ or compatible derivatives; the portable archive is best effort on other modern glibc-based x86-64 systems and does not support Alpine/musl or ARM.