FT-IR OM, OC, EC and functional groups

FTIR graphic
AQRC researchers are developing methods of using FT-IR spectroscopy to help quantify the composition of airborne particles. The graph above shows the characteristic FT-IR spectroscopic absorbance of adipic acid, (CH2)4(COOH)2, an atmospherically relevant carbon molecule. Image: Ann Dillner

The Air Quality Research Center is conducting an ongoing research program to develop FT-IR (Fourier transform-infrared spectroscopy) methods to measure functional groups, organic matter (OM), organic carbon (OC) and elemental carbon (EC) in particles collected on Teflon© filters.  Direct measurement of OM is useful because current methods require using an estimated organic mass/organic carbon ratio—OM/OC—to convert measured OC to OM. Organic functional groups are summed to determine OM and they provide information for identifying sources and understanding atmospheric processes of organic aerosols.  FT-IR calibrated to thermal/optical reflectance (TOR) OC and EC using partial least squares regression is a cost effect method for obtaining TOR data for intensive sampling campaigns and major monitoring networks.

Our Lab Equipment

The FTIR laboratory has 3 Bruker Tensor FT-IR instruments with liquid nitrogen detectors which can quantify organic and elemental carbon, organic functional groups such as aliphatic CH, carbonyl, carboxylic OH, alcohol OH, and organic nitrogen (amine) and organic matter (OM) from Teflon filter PM2.5 samples.  Below is a picture of the lab.

FT-IR Carbon Instrument

Contact—Ann Dillner (530-752-0509)