Selected ion flow tube mass spectrometry (SIFT-MS) is a portable chemical ionisation technology designed to measure gases with high temporal resolution, detecting concentrations as low as pmol mol-1. In SIFT-MS analyses, H3O+, NO+ and O2+ are used as reagent ions, avoiding interference from major air components and eliminating the need for sample pretreatment. The reagent ions are rapidly preselected using a quadruple mass filter between the ion source and reaction chamber. SIFT-MS is also compatible with both positive and negative ion modes, as well as with flammable gases.
The SIFT-MS process incorporates a quadrupole mass filter to enable real-time analyte measurements. This capability has made SIFT-MS invaluable in applications requiring immediate measurements:
Manufacturing – for cleanroom air monitoring and quality control
Medical diagnostics – for non-invasive breath analysis to assess metabolic health and disease
Air quality monitoring – for analysing volatile organic compounds (VOCs) from industrial and natural sources
Foods and flavours – for assessing aroma profiles in product development and quality improvement
Regular calibration with traceable primary reference materials (PRMs) is crucial for reliable and reproducible SIFT-MS measurements (Langford et al., 2023, doi:10.1021/jasms.3c00312). However, a lack of high-quality, traceable calibration gas mixtures on the market currently poses challenges for cross-comparability in studies and monitoring projects, highlighting the need for consistent, stable gas reference materials for SIFT-MS.
NPL is the highest point of traceability and addresses this gap by offering a unique selection of PRMs specifically designed for SIFT-MS applications, including an eight-component gas reference material with an impressive five-year stability. These cost-effective standards support accurate, long-term performance across a wide range of sectors, from environmental monitoring to occupational health and safety, establishing global benchmarks and instilling confidence in your SIFT-MS calibration and results. The composition of this standard includes the following compounds at nominally 2 μmol mol-1 within a nitrogen balance gas. The uncertainties for each compound are in the range of 3-5 per cent.
| 1,2,3,4-tetrafluorobenzene | benzene | isobutane |
| octafluorotoluene | p-xylene | hexafluorobenzene |
| ethane | toluene |
Note: Commonly used names are shown here but the preferred IUPAC names where appropriate are: 2-methyl propane (isobutane), 1,2,3,4,5-Pentafluoro-6-(trifluoromethyl)benzene (octafluorotoluene) and 1,4-Xylene (p-xylene).
Find out more about Mass spectrometry calibration (PTR-MS)
Download our comprehensive eBook to explore these cutting-edge technologies, their applications and the crucial role of calibration in achieving trustworthy and comparable measurements.
We created our eight-component PRMs in collaboration with the global SIFT-MS community in order to address the most common calibration requirements. However, our diverse in-house skillset and extensive experience give us the flexibility to provide bespoke mixtures containing different compounds and amount fractions to suit your niche applications.
To discuss your specific requirements, contact us using our online form, or call our Customer Services team on +44 20 8943 7070.
New calibration approach and new NPL reference materials will enable more widespread deployment of proton transfer reaction mass spectrometers (PTR-MS) for long-term atmospheric monitoring.
Our research and measurement solutions support innovation and product development. We work with companies to deliver business advantage and commercial success.
Contact our Customer Services team on +44 20 8943 7070