Food Safety and Environmental Stewardship Program

Forage nitrate (NO3) analytical methods have shown biases. Extraction of plant material has not been standardized for NO3 analysis. Significantly different extraction techniques are currently used by professionals in the field, often depending on the professional discipline or analytical detection method. The effects of extraction variables has not been adequately examined. In this paper, five different extraction variables were investigated, including sample size, extraction volume, extraction shake time, extraction temperature, and extraction solution pH. The effects of the extraction variables were determined for three commonly used analytical detection techniques, including flow injection analysis, ion chromatography, and ion specific electrode.