The Analytical Breakthrough You Want To Know About

Martin Perkins

23rd July 2020

Filtration, FTIR, SIFT-MS, VIAQ, VOC Analysis,

You’re sitting in your car. The air-con is set to outside air. A very informative Radio 4 program about at-street-level air pollution rings through the speakers.

You hit traffic. Dozens of cars and buses chuck out potentially harmful volatile organic compounds (VOCs).

A wave of relief washes over you. You know your car’s air filter is preventing the nasty stuff getting into your bubble of comfort and safety.

But of course it’s not that simple.

Many of us think that a filter will remove everything that is thrown at it. We give little thought to how long it will absorb or filter compounds or particles from the air stream. As we know from making coffee or vacuuming our homes, filters need cleaning or replacing periodically to remain effective.

The filtration ability of a material can be affected hugely by environmental conditions, such as humidity and temperature.

The question is how do we measure this to understand the effectiveness of the filter and the safe levels for the air that needs filtering?

Whenever we conduct testing we must understand the merits and limitations of the methods used. For example, FTIR is often used to measure VOCs. However the technique is limited by the large effect humidity has on it. Additionally, it is relatively insensitive and non-specific.

Therefore, humidity may not be of direct concern, but it is useful to measure it in tandem.

Recent Investigations

We’ve recently been investigating the use of SIFT-MS for this application for a few of our customers and for a number of reasons:

  • The SIFT-MS measures humidity and accounts for potential product clusters in concentration calculations.
  • The SIFT-MS can measure a wide range of compounds (both polar and non-polar) in one method meaning you can cover your whole suite of analytes with one technique in one run or on one sample, reducing the requirements for multiple analyses to be run.
  • It’s inherently quantitative (this can be further improved with calibration)
  • It has a large dynamic range enabling measurement of both high-challenge concentration and low-breakthrough concentration.
  • It offers extremely fast, real-time analysis giving enhanced information on breakthrough times. This is very important when considering things like PPE.
  • With the addition of the 14-port inlet and heated transfer lines you can easily and quickly switch, via software, between the points on your test rig that you need to sample.

In essence, by measuring continuously and getting real time results, Thermal Desorption SIFT-MS gives us the ability to better understand the exact moment when a filter lets through an unacceptable concentration of particles or compounds and see the shape of the curve.

Now we have Thermal Desorption SIFT-MS available, we can also obtain cumulative data over the life of the filter, in addition to pinpointing the exact moment the filter fails its specification.

Will this new technique work for your application? There is only one way to find out – try it! To arrange a demonstration on your samples, call us on +44 (0)1223 279 210 or email