NexChrom · GC software for natural gas
Take control of your gas chromatography data.
One application. Every step. From raw CDS data to reviewed, certified results for natural gas and calibration gas mixtures — with GUM uncertainty on every mole fraction.
Natural gas
composition by GC, from CDS file to certificate
ISO 6974 · 6976
natural gas analysis and gas properties
QC charts
control charts with automatic checks on every QC run
4-eyes
release of runs, models and certificates
The problem
Stop stitching your lab together.
Peak tables in the chromatography data system, the calibration in a spreadsheet, the uncertainty in another, the certificate in a word processor — and a review that depends on who has time. NexChrom brings it into one application, with one record of what was done.
Results you can defend
Every mole fraction comes with its uncertainty, and with the calibration model, the source file and the approval behind it.
Less manual work
Import, calibration, uncertainty and certificate in one flow — no numbers copied between programs, no formulas to check.
Quality in the workflow
QC samples on control charts with automatic checks; a failed QC run cannot be approved, and every release takes a second pair of eyes.
How it works
Complete analytical workflow
NexChrom guides you through every step — intuitively, accurately, and traceably.
- Instrument and sample setup — register GC instruments, locations and samples; import CDS files.
- Method configuration — define component roles: direct (calibrated), indirect (via relative response factors) or fixed (certified value).
- Calibration — polynomial models with errors-in-variables regression (ISO 6143) pre-selected, or OLS, WOLS and GLM; the model order is suggested from the fit.
- Execute and calculate — mole fractions with GUM uncertainty propagation, normalised composition and flagging of results outside the calibrated range.
- Review and approve — runs, calibration models and certificates are released by a second person; every decision is recorded.
- Certificates — analysis certificates as frozen PDFs; reference certificates imported from PDF with OCR and checked at approval.
Calibration
Full statistics, not just a fitted line.
Every fit shows coefficients with their uncertainties, covariance and correlation, residual diagnostics and an intercept test. Replicates per calibration point are shown on a control chart with a Grubbs outlier test and can be excluded per model.
Calibration models are versioned and archived — never overwritten.
Quality control
- QC limits from the history of approved runs, from the certificate of the QC sample, or entered by hand.
- Control charts with automatic rule checks (Westgard); a failed QC run cannot be approved.
- A calibration model is released only after a QC sample measured in its session has passed.
- A dashboard with alerts, the review queue and a status line per instrument.
Data import
- Native import of Agilent ChemStation and Scion/Bruker CompassCDS data files.
- Generic CSV, Excel and text exports from other systems, such as processed exports from Thermo Chromeleon.
- Component names matched through aliases, globally or per instrument.
- Every imported file stored with its hash.
Standards
Built on the standards your auditor knows.
- ISO 6974 — natural gas composition by gas chromatography
- ISO 6974-2 — uncertainty of relative response factors
- ISO 6976 — calorific value, density and Wobbe index of natural gas
- ISO 6143 — errors-in-variables calibration
- JCGM 100 (GUM) — uncertainty propagation
- ISO/IEC 17025 — review, audit trail and QC
Stand-alone and secure
NexChrom runs locally on a Windows computer and is used in a web browser; your data stays in a local database. No cloud account, no outside service it depends on. An optional AI assistant is the only part that goes online — NexChrom works fully without it.
See NexChrom at work
From importing a CDS file to an approved certificate — we gladly show you NexChrom live. Book a demo or ask for a quote.