Overview
EN ISO 2620:2024 - Analysis of natural gas / biomethane - specifies a validated method for sampling and analysis of volatile organic compounds (VOCs) using thermal desorption gas chromatography with flame ionization and/or mass spectrometry detectors (TD‑GC‑FID/MS). The standard covers VOC classes commonly found in biogas and biomethane such as siloxanes, terpenes and organic sulfur compounds, and supports quality control and conformity assessment for biomethane used in the gas grid and as a transport fuel.
Key Topics and Requirements
- Scope and principle: Sampling a measured gas volume through a sorbent tube where VOCs are retained; thermal desorption releases analytes to a capillary GC with FID and/or MS for identification and quantification.
- Target analytes: Broad VOC groups including siloxanes, terpenes, hydrocarbons, oxygenated and halogenated hydrocarbons, ketones, alcohols, esters and organic sulfur compounds.
- Sampling media: Use of preconditioned sorbent tubes compatible with TD instruments (example sorbent: 2,6‑diphenyl‑phenylene oxide polymer is cited).
- Calibration and reagents: Calibration standards of individual VOCs with purity > 99 %; dilution solvents of chromatographic quality (e.g., methanol or diethyl ether) free from target compounds.
- Analytical performance: Expected quantification limits around 2–5 ng on-tube (~20–50 µg/m3 in sampled gas assuming a 100 ml sample).
- Identification: Combines MS mass spectral matching, selected ions, and retention indices; FID and/or MS used for quantification.
- Quality assurance: Includes field blanks, liquid spiking procedures and standard tube loading for method traceability and performance verification.
- Normative reference: Uses ISO 14532 for natural gas terminology.
Applications - Who Uses This Standard
- Laboratories performing VOC analysis in natural gas and biomethane for compliance testing.
- Biogas and biomethane producers verifying gas quality after upgrading and before injection into grids or sale as fuel.
- Gas network operators and regulators enforcing grid injection specifications and emissions control.
- Environmental and contract testing labs offering TD‑GC‑FID/MS services for siloxane and terpene monitoring.
- Equipment manufacturers and developers validating analytical workflows and sorbent tube compatibility.
Related Standards
- ISO 14532 (Natural gas - Vocabulary) is referenced for terms and definitions.
- Developed by ISO/TC 193 in collaboration with CEN/TC 408 to support biomethane specifications for grid injection and transport fuel markets.
Keywords: EN ISO 2620:2024, biomethane analysis, VOC determination, thermal desorption, TD‑GC‑FID/MS, siloxanes, terpenes, organic sulfur compounds, natural gas testing.