PTR-MS for Ultra-Sensitive Real-Time Monitoring of Air Pollutants

Due to their fast response-times and ultra-low detection limits, IONICON PTR-MS systems are indispensable tools in environmental research, helping scientists worldwide to better understand the world humans live in.

environmental research

High Resolution Monitoring of Roadside-Air VOCs

Not only does the IONICON PTR-TOFMS series feature a very low detection limit for most common VOCs but it also delivers results with a very high mass resolution and quantification of the whole unlimited mass range in a single scan, enabling customers to discriminate isobars and get considerably more information from the collected data.

TOF data

TOF data

A good example of low concentrated isobars detected using a PTR-TOF 8000 is depicted in the graph above. Both compounds have the same nominal mass and therefore cannot be differentiated using a quadrupole based instrument. A PTR-TOF, however, makes it possible to separate and identify them as C4H10O (e.g. dimethylethanol) at 75.081 and C3H6O2 (e.g. acetic acid methyl ester or formic acid ethyl ester) at 75.0446.

Mobile PTR-MS Solutions

IONICON’s instruments are ideally suited for field campaigns, as a lot of researchers have successfully proven over the last 10 years. Among these researchers, Prof. Berk Knighton, Montana State University, has installed an IONICON PTR-MS in a mobile lab to track engine exhaust in real-time, "chasing" single vehicles in Mexico City Metropolitan Area's traffic. It was demonstrated that the results vary based on the driving behavior, fuel quality and vehicle condition.

This experiment can be viewed in an illustrative video sequence (15 Mb, quicktime, courtesy of Prof. Knighton). The video shows a picture of the vehicle being monitored in the upper left hand. On the bottom is the evolution of two signals: (1) CO2, a combustion tracer to confirm that the mobile lab is intercepting the vehicles’ exhaust plume; and (2) PTR-MS signal at m/z 57, a fragment from MTBE, an additive in Mexican fuel. In the upper panel, a correlation scatter plot of the m/z 57 signal (in ppbv) vs. the CO2 concentration is shown. The slope stands for the emission ratio.

IONICON Analytik

This information has been sourced, reviewed and adapted from materials provided by IONICON Analytik.

For more information on this source, please visit IONICON Analytik.

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