Measurement and Calibration Services

WACL hosts advanced capabilities for the analysis of trace chemicals in gases and aerosols. Our measurement capabilities include:

  • Non-methane hydrocarbons C2 - C14 as gases and C6-macromolecules in aerosols
  • Oxygenated compounds including alcohols, aldehydes and ketones as gases and aerosols
  • Organo-nitrogen compounds in aerosols and particulate matter
  • Halocarbon gases, including ozone depleting substances
  • Classical air pollutants including NOx, CO, SO2, O3, PM
  • Greenhouse gases, CO2, CH4, N2O

Whilst the main focus of our research is the measurement of atmospherically important compounds, the experience of staff extends far beyond this subject area and our state of the art, highly sensitive instrumentation can be employed in many other applications. If you have a related trace measurement requirement that’s not listed here, or would like more detailed information on the methods and techniques we use, then please get in touch at wacl@york.ac.uk.

We have worked on numerous challenging non-standard trace measurement problems for organisations such as BP, TOTAL, Unilever, Givaudan, Du Pont, and DSTL. Our collaborations can range from pay-per-sample through to multi-year research projects.

For further information on services available, please follow the tabs below:

VOCs

WACL offers analysis of air samples collected in either glass or steel sample canisters or Tedlar bags. We can provide provide quantification of gaseous Volatile Organic Compounds (VOCs) (C2 up to C14, and including halogenated VOCs) using thermal desorption coupled with either Gas Chromatography - Flame Ionisation Detection (GC-FID) or Gas Chromatography - Mass Spectrometry (GC-MS), and for individual VOC abundances as low as 1 part per trillion in air. We can provide species identification and quantification (from the parts per million down to parts per trillion ranges) with all data traceable to certified gas mixtures. Typical precision of measurements is around 5% for most compounds.

Potential applications

  • Ambient air monitoring, including fenceline and fugitive emissions
  • Indoor air quality
  • Natural gas leakage assessment
  • Engine exhaust performance assessment
  • Clean-room pollution
  • High purity gas contaminant evaluation
  • Semiconductor production environments

We can supply loan sampling apparatus including canisters, tedlar bags, pumps and time averaging sample inlets.

Aroma profiling & olfactory assessment

Our labs are equipped with state of the art high accuracy mass spectrometry that we have optimsed for the detection of trace organic species in gas mixtures. Using gas chromatography coupled to high resolution mass spectrometry and an olfactory port, we can offer trace level identification and quantification of odour causing compounds. We can provide a profile of the odour active compounds from air/gas, liquid or solid samples and generate standard mixtures pf gases for calibration and quantification.

Potential applications

  • Monitoring of odorous emissions e.g. from processing plants, tips or toilets
  • Identification of odour causing compounds from unknown samples e.g. paints, food, drinks or perfumes
  • Profiling of aroma causing compounds from various samples (allowing comparison between samples, specifically relating to odour)

High pressure gas sampling

WACL have developed an ultra clean high-pressure air sampling system. This can fill canisters/cylinders up to 200 bar with no contamination or alteration of the sampled air or gas, for use as working gas standards or in applications where very large volumes of sample are required.

Potential applications

  • Large volume, clean air sampling
  • Creation of highly characterised air samples for use as standards in further analysis

Dynamic calibration & gas dilution systems

WACL can design and build customised dynamic dilution delivery systems that deliver known quantities of reference gas materials over the part per trillion to part per million range. These calibration systems allow complex mixtures of reference compounds to be blended and delivered at trace levels in a controllable gas stream or either air, nitrogen or any other stable balance gas. Our systems can work with unstable/labile compounds, and do not require the long equilibration periods associated with permeation calibration sources.

Potential applications

  • Creation of trace gas VOC calibration mixtures blending up to 10 compounds mixed in varying proportions
  • Instant generation of mixtures of VOC for immediate use (removes any degradation of reactive species when stored in cylinders for extended periods)