Fireworks: a sight for sore eyes and a cause of a sore throat. ECN’s MARGA infallibly identifies the peaks in the measured concentrations (below) in Schiedam (NL), the home of MARGA manufacturer Applikon.

In 2006 ECN introduced a new instrument called MARGA to accurately measure the air pollutants ammonia, nitric acid, sulphur dioxide and particulates from hour to hour. There was great international interest for the innovation. ECN licensed the Schiedam company Applikon Analytical to develop the instrument for production and for the market. Such development would usually take some ten years. How far is Applikon now?

According to Timoer Frelink, General Director of Applikon Analytical, sales are starting to take off. “We have delivered four MARGAs to South Korea for measurements in and around the capital Seoul. The Scottish government has been using the system for three years already, and a second MARGA has just been ordered for England. We have also received orders from China, Finland, the Institut für Tropospherische Forschung, in Leipzig, and the American EPA (Environmental Protection Agency). We haven’t actually sold anything in the Netherlands yet, despite all the focus on and fuss about particulate matter.”
The EPA ordered three instruments straight away in 2006. But it soon emerged that various points needed improving. The measuring results were good but the instruments themselves were not reliable enough. The EPA also wanted proof that all aerosols would actually be measured and that the so-called peak loads of sulphur dioxide concentration in the air would be registered. Frelink: “The discussion led to a new 15 million dollar contract in 2008.  It was agreed that after the demonstration phase, during which specific EPA requirements would be taken into account, the EPA will order MARGAs for the so-called CASTNET.” 

MARGA tested with ‘model gases’
Mr Frelink explains how MARGA (Monitoring Instrument for AeRosols and GAses) works: “Air is sucked in from outside though a tube. Firstly the coarser particles such as flies and leaves are filtered out. The air is then passed through water and, because of their high diffusion speed, only volatiles such as sulphur dioxide, ammonia, nitric acid and chlorides will dissolve. The aerosols, the ‘particulates’ you might say, are then dissolved separately in water. There are consequently two watery solutions to analyse. Dissolving the substances in water makes the analysis easy. We do this using ion chromatography. The MARGA does this fully automatically, day in day out.”
Someone comes in to refresh the solutions once a week. Frelink: “It was not clear initially whether or not everything was indeed measured but we’ve mastered that now. To be absolutely sure we tested MARGA with model gases of which the composition was known. We also added extra ammonia to the ambient air to check that the instrument registered the peak in ammonia concentration. The tests revealed that MARGA does it all nicely.”
Registering a peak might seem obvious but traditional measurement methods, like those still used by the RIVM (the National Institute for Public Health and the Environment) in the Netherlands for instance, conduct measurements for a whole day and the result is the average concentration of a particular substance over that day. You consequently see no highs or lows and cannot tell what the effects are of heavy rush hour traffic, for example. “The fact that MARGA registers and records the variations in concentration of the various substances over time is what makes this instrument unique. That is why the EPA is so interested in MARGA”, Frelink emphasises.

ECN’s rule of thumb proved accurate
Four employees of Applikon and an ECN software developer are currently working on the further development of MARGA. “Up to now we have been able to sell the system to institutes that know very well what they can do with the instrument, people who can tinker with it themselves if need be; people who understand it, in other words. We expect to need a little more time to make the instrument reliable and user friendly enough to be able to sell it to everyone. So ECN’s rule of thumb for a commercial development period of ten years is right in our case”, Timoer Frelink says.
He also expects that MARGA will become profitable for Applikon in two years time. “Up to now MARGA has only cost us money. But we persevere. Analysing gases is an interesting new field for us.
This is a new discipline besides the field we’ve already been active in for years:
the production and sales of equipment for online wet-chemical analyses of fluids and emulsions in industry.”

The RIVM works with averages, not with peaks. This makes tracing a source extremely difficult. MARGA analyses the particulates and will also be able to determine quantities. Slowly but surely source determination is getting closer.

Industry interested in MARGA
The process industry is a potential customer for MARGA. Several sectors of industry recently put their heads together and decided to chart particulate matter accurately in accordance with a specific protocol. This is quite difficult and, in effect, leads to estimates. Following the discussions with the government on particulate matter emissions the industry wants hard figures. MARGA is just what is needed, as this instrument measures the composition of particulates up to 2.5 or 10 micron in diameter (1 micron is one thousandth of a millimetre) accurately. Moreover, MARGA also measures the volatile inorganic substances such as ammonia and sulphur dioxide.  MARGA can bring the industry a step closer to accurately measuring particulate matter.
Finally, Applikon also keeps a finger on the pulse of the EMEP (European Monitoring and Evaluation Programme) and the European programmes that monitor air pollution. In this monitoring programme MARGA is a promising newcomer.

Text: Erik te Roller

Contact
René Otjes
ECN Biomass, Coal & Environmental Research
Phone: +31 (0)22 456 4264
E-mail: René Otjes  

Info
Click here to see what ECN has to offer in the field of Instrument development.
Applikon, manufacturer of MARGA: www.applikon.com

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