Monitoring and improving air quality
Ozone precursors
NPL is the Central Calibration Laboratory (CCL) for non-methane hydrocarbons (NMHCs) within the World Meteorological Organisation Global Atmospheric Watch programme (WMO-GAW).
NPL provides a 30-component primary reference material (PRM) that contains all the ozone precursor hydrocarbon compounds listed in Annex X of the European Directive 2008/50/EC on Ambient Air Quality and Cleaner Air for Europe. These mixtures are typically prepared at amount fractions of 4 nmol/mol, but other amount fractions from 1 to 200 nmol/mol are also available.
| Ethane |
1,3-butadiene |
2,2,4-trimethylpentane |
| Ethene (ethylene) |
Pentane |
Benzene |
| Ethyne (acetylene) |
2-methylbutane |
Toluene |
| Propane |
1-pentene |
Ethylbenzene |
| Propene |
trans-2-pentene |
m-xylene |
| Butane |
2-methyl-1,3-butadiene (isoprene) |
p-xylene |
| 2-methylpropane (i-butane) |
Hexane |
o-xylene |
| 1-butene |
2-methylpentane |
1,2,3-trimethylbenzene |
| trans-2-butene |
Heptane |
1,2,4-trimethylbenzene |
| cis-2-butene |
Octane |
1,3,5-trimethylbenzene |
BTEX mixtures
NPL provides a range of BTEX PRMs containing benzene, toluene, ethylbenzene, m-xylene, p-xylene and o-xylene at amount fractions from 1 nmol/mol to 10 µmol/mol. Mixtures containing BTEX and 1,3-butadiene are also available.
Oxygenated VOCs (OVOCs) including formaldehyde
NPL offers a range of OVOC PRMs at amount fractions of 1 to 10 μmol/mol. One typical multi-component mixture contains the components shown below. Mixtures containing other OVOCs (e.g., acetaldehyde, acetonitrile, methyl ethyl ketone) are available on request. Binary mixtures of formaldehyde are also available on request in amount fractions of 1 to 10 μmol/mol.
|
Methanol
|
Ethanol
|
Acetone
|
|
n-hexane
|
Propane
|
Benzene
|
Bespoke mixtures
NPL can provide, on request, bespoke PRMs containing C2 to C10 hydrocarbons, chlorinated hydrocarbons and fluorinated hydrocarbons at a range of amount fractions. For example, PRMs of perdeuterated toluene (d8-toluene) are available due to their use as an internal standard in GC-MS applications. We can provide these mixtures at a range of amount fractions but most commonly at 5 µmol/mol.
Download the User Guide for NPL VOC Standards
Terpenes
Multi-component terpene mixtures
NPL provides a range of terpene primary reference materials (PRMs) at amount fractions from 1 to 200 nmol/mol. One typical multi-component terpene mixture contains the components shown below.
| (+/-)-α-pinene |
(+)-3-carene |
| 1,8-cineole (eucalyptol) |
R-(+)-limonene |
Mixtures containing other terpenes, such as β-pinene, myrcene, camphor, p-cymene or cis-ocimene, are available on request.
33-component ozone precursor and terpene mixture
NPL can provide a PRM containing all 30 components of the ozone precursor mixture, as well as α-pinene, β-pinene and limonene. This mixture is available at a range of amount fractions from 2 to 10 nmol/mol. Other components may be included and these terpenes can also be combined with just the BTEX components on request.
Don’t see what you are looking for? Our diverse skill set enables us to provide bespoke solutions. Please contact us to discuss your requirements.
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