Straightforward Determination of Anhydrosugars in Aerosols

Metrohm presents a new method for the sensitive and robust routine determination of the «smoke markers» levoglucosan, mannosan and galactosan in aerosols. The method couples ion chromatography
with a highly sensitive pulsed amperometric detector (IC-PAD) and provides a simple and less expensive alternative to GC/MS. As such, it facilitates research into the effects of biomass burning aerosols on meteorological
phenomena and on the climate in general.

Anhydrosugars are thermal degredation products of cellulose and hemicellulose. They form an important fraction of watersoluble organic carbon in atmospheric aerosols and thus have a great potential of affecting, among others, cloud formation and precipitation and thus the climate in general.

The analytical method couples ion chromatography with a highly sensitive pulsed amperometric detector (IC-PAD). In the test, a Metrosep A Supp 15 – 150 was coupled to a Metrosep Carb 1 – 150. The calibration for the
anhydrosugars and sugar alcohols is linear over a wide concentration range. Less than 17 minutes were needed to achieve separation with a limit of detection (LOD) for levoglucosan of approximately 5 ng/m3.

For sample preparation, the aerosol fraction of a defined air volume is collected on a filter. Before extraction, this filter is divided in samples of a standardised size. After addition of ultrapure water, the filters are treated by ultrasonic extraction for about 30 minutes. Prior to injection, the samples are either filtrated through a syringe filter or by using Metrohm’s Inline Ultrafiltration.