A wet chemical sampling method using acidic absorbing solutions was used to determine levels of ammonia (NH3) in syngas from a biomass gasifier. Before syngas is bubbled into the absorbing solutions, a quartz thimble filter is used to filter ash from the gas stream at 450 degrees C followed by heavy tar removal at about 100 degrees C. When gasifying corn, good precision was observed for multiple samples collected on any given day of testing. Tests on producer gas obtained from gasification of switchgrass revealed important conditions for successfully sampling NH3. During gasification of switchgrass, high solids loading in the syngas caused the primary cyclone at the gasifier exit to plug, resulting in abnormally high ash loading in the thimble filter in the sampling system. While gasifying the switchgrass, the NH3 levels showed a continuous decline throughout the day. It is suspected that NH3 reacts with the ash in the thimble filter, confounding attempts to accurately measure NH3 in the syngas.