Analysis of Amines from Animal Agriculture

Oral Presentation

Prepared by S. Trabue, K. Scoggin
USDA ARS, 1015 N. University Blvd, Ames, IA, 50011, United States


Contact Information: [email protected]; 515-294-0201


ABSTRACT

Air quality in rural communities is negatively impacted by odors from animal production. One of the poorest understood odorants are amines due in large part to the high concentrations of ammonia that often interfere with amine analysis when using ion chromatography for quantitation. A rapid automated method for the determination of amines trapped in acid solutions was developed for headspace analysis using a multipurpose sampler (MPS) with solid phase microextraction (SPME) and GC-MS analysis. The extraction conditions such as extraction mode (i.e., liquid or headspace), pH, salt addition, extraction temperature, sample volume, and extraction time were examined. The MPS was used to control both the extraction temperature and extraction time. Denuder extract (1-5 mL) were pH (11-13) and salt (0-40% w/w ) adjusted prior to incubation on the MPS. The MPS incubated of extracts (10-25 min) at elevated temperatures (25-100oC) and extracted time (0.5-180 min) prior to analysis by GC-MS. Critical factors lowering the limit of quantitation included the temperature of incubation, salt content, and pH, while critical factors improving the robustness of the method include extraction times, pH, and salt content. The factors controlling the speed of analysis include incubation time and initial GC column starting temperature. Fiber degradation was strongly influenced by incubation temperature and final pH of extract. Calibration of the SPME fiber was performed by both external standards and standard addition both of which gave similar results. Key amines detected included methylamine, dimethylamine, trimethylamine.