Overview
EN ISO 19739:2005 (ISO 19739:2004) specifies standardized procedures for the determination of sulfur compounds in natural gas using gas chromatography (GC). The standard covers identification and quantification of key sulfur species including hydrogen sulfide (H2S), carbonyl sulfide (COS), C1–C4 thiols (alkane thiols/mercaptans), alkyl sulfides/disulfides and tetrahydrothiophene (THT). Multiple GC-based methods are provided in informative annexes; whichever method is chosen, the general requirements of the standard apply.
Key topics and technical requirements
- Analytes covered: H2S, COS, thiols (mercaptans), sulfides, disulfides, THT and other common natural gas sulfur compounds.
- Analytical principle: Physical separation by GC followed by measurement versus calibrated reference gases; calibration gas and sample must be analyzed under identical conditions.
- Apparatus and columns: Use GC systems with injection, oven temperature and pressure control; column materials and stationary phases must be inert to sulfur and provide chromatographic resolution of at least 1.5 between adjacent peaks.
- Detectors and methods (annexes): Multiple detectors/methods are described (examples in annexes): flame photometric detector (FPD), sulfur chemiluminescence detector (SCD), pulsed flame photometric detector (PFPD), mass spectrometry (MSD), atomic emission detector (AED), electron capture/other detectors (ED), and column-switching approaches - allowing selection to match sensitivity and selectivity needs.
- Sampling and safety: Guidance on sampling practice, temperature and pressure control, materials, purge and flow control; includes a safety warning that some sulfur compounds are hazardous.
- Calibration and traceability: Requirements for calibration using primary/secondary/working reference gas mixtures and references to ISO documents on gas mixture certification and comparison.
- Performance characteristics & reporting: Specifies required performance characteristics for sulfur analyses and test-report content.
Applications and users
- Utilities and pipeline operators monitoring odorants and residual sulfur in distribution/transmission systems.
- Natural gas producers and processing plants (quality control and treatment validation).
- Analytical laboratories performing regulatory compliance, process control, or environmental monitoring.
- Manufacturers of GC equipment and detectors aligning test methods with industry standards.
- Regulators and standards bodies specifying measurement requirements for safety and billing specifications.
Related standards
Normative references cited by ISO 19739 include:
Keywords: EN ISO 19739:2005, ISO 19739, natural gas, sulfur compounds, gas chromatography, hydrogen sulfide, thiols, sulfides, THT, GC detectors, calibration gas, sampling.
