ISO 14965:2000 PDF

Overview

ISO 14965:2000 specifies a laboratory procedure for measuring total non-methane volatile organic compounds (NMVOC) in ambient air using cryogenic preconcentration and direct flame ionization detection (FID). The method collects integrated air samples in passivated stainless-steel canisters (typically 4–6 L) using pressurized sampling (final pressures above atmospheric), concentrates NMVOC on a cryogenic trap (recommended cryogen: liquid argon, ~87 K), then thermally desorbs the organics into an FID for direct total-carbon response. The standard covers the analytical range from 20 ppbC to 10 000 ppbC and provides options for method variations and range extension.

Key topics and requirements

• Sampling: Integrated ambient sampling into cleaned, electropolished stainless-steel canisters; unique canister identification and pressurized fill procedures.
• Cryogenic preconcentration: Fixed-volume sample drawn through a glass-bead trap cooled to ~87 K to retain NMVOC while letting N2, O2 and methane pass through. Trap is later heated (≈353–363 K) to release organics.
• Detection: Direct FID measurement with helium carrier gas; near-unity hydrocarbon response minimizes compound-dependent sensitivity differences. Calibration typically uses propane (ppmC/ppbC units = concentration × carbon atoms).
• Calibration & quantification: Dynamic calibration and integrated-peak area vs. known propane concentrations. System must be precisely repeatable between calibration and analysis.
• Performance & QA: Procedures for canister cleaning, leak checks, blank checks, SOPs, precision and accuracy assessments.
• Interferences & limitations: Moisture can shift FID baseline; oxygenated or halogenated organics may be underrepresented. Not intended for continuous ambient monitoring or detailed species separation.

Applications and practical value

• Ambient air quality monitoring for ozone/photochemical-smog precursors where total NMVOC concentration is required rather than species profiles.
• Remote and integrated sampling - collect at remote sites and analyze centrally; supports replicate sampling and multi-site campaigns.
• Canister screening and cleanliness checks prior to species-level gas-chromatographic analysis.
• Useful for regulatory monitoring, research studies of VOC transport, and baseline/rural site monitoring.

Who should use this standard

• Environmental monitoring agencies, accredited air quality laboratories, research institutions, and industrial/compliance labs needing standardized NMVOC total-carbon measurements from canister samples. Instrument and canister manufacturers will also use the standard for design and validation.

Related standards

• ISO/TR 4227 (ambient air monitoring planning)
• ISO 6141; ISO 6145 series (gas analysis and calibration gas preparation)