Vaughan Langford Syft Technologies Director - Applications & Marketing

Dr. Vaughan Langford

BSc(Hons), PhD

Principal Scientist / Consultant


Trash being dumped into a landfill

Siloxanes are volatile silicon-containing organic compounds that are widely used as ingredients in cosmetic products and as antifoaming agents, lubricants, and food additives. The so-called Cyclomethicones are particularly widely used:

  • octamethylcyclotetrasiloxane, D4
  • decamethylcyclopentasiloxane, D5

Although D4 and D5 are relatively innocuous compounds to humans (see the European Community’s Scientific Committee on Consumer Safety (SCCS) publication, Opinion on cyclomethicone D4/D5, 22 June 2010 (ISSN 1831-4767; ISBN 978-92-79-12742-7; doi:10.2772/24205), the widespread usage of these compounds means that they find their way into landfills. Here they can cause significant issues during environmentally friendly conversion of methane-rich landfill gas to carbon dioxide and electricity. At the elevated temperatures in combustion, siloxanes such as D4 and D5 convert to silica, which reduces generation efficiency and accelerates engine wear.

To reduce this risk, landfill gas is passed through a siloxane scrubber before reaching the turbine. Monitoring the efficiency of the scrubber is important in ensuring efficient performance of the turbine and minimizing preventative maintenance and avoiding costly damage.

Traditional methods for siloxane analysis are slow, labor-intensive, and lack the sensitivity required for effective post-scrubber detection.

SIFT-MS is an ideal technique for both laboratory and online, sensitive siloxane detection, as shown in two papers that we published in 2013:

    • 1.“Selected ion flow tube studies of several siloxanes”, V.S. Langford, J.D.C. Gray and M.J. McEwan, Rapid Commun. Mass Spectrom., 2013, 27, 700–706.


    2.“Detection of Siloxanes in Landfill Gas and Biogas Using SIFT-MS”, V.S. Langford, J.D.C. Gray, R.G. A. R. Maclagan and M.J. McEwan, Current Analytical Chemistry, 2013, 9, 558-564.

Syft Technologies Voice200ultra instruments provide a unique solution for comprehensive siloxane detection:

  • Direct analysis of siloxanes in air and landfill gas without sample treatment or pre-concentration
  • Detection limits in the part-per-trillion range for effective siloxane detection post-scrubber
  • Wide linear and dynamic range for pre- and post-scrubber analysis
  • Rugged, simple-to-use design that is industry proven.

Posted by Dr Vaughan Langford, Director of Applications and Marketing at Syft Technologies.

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