title: Technical note: an improved method for extraction and quantification of toxic phenethylamines from Acacia berlandieri.
abstract: N-methyl-beta-phenethylamine (NMPEA) has been previously identified as the toxin causing locomotor ataxia in sheep and goats grazing the browse plant, Acacia berlandieri. We describe a simplified procedure for extraction and quantification of naturally occurring beta-phenethylamines from this Acacia species. Dried, ground plant tissue was extracted (1:20 wt/vol) with 1% glacial acetic acid and filtered. The filtrate was passed through a high-sulfonated polymeric solid-phase extraction (SPE) tube, which retained the compounds of interest (tyramine, hordenine, NMPEA) but allowed many impurities co-extracted from the plant tissue to be washed through. Amines were eluted from the tube, then separated and detected by reversed-phase HPLC. Extracted amines were resolved by HPLC in < 15 min, and UV-absorbance spectra matched those of authentic standards. Recovery efficiency of amine standards (125 micrograms/mL) from SPE tubes averaged 97, 101, and 98% for tyramine, hordenine, and NMPEA, respectively. Excess sample loss was prevented and the large volumes of solvents required for liquid-liquid extraction eliminated by use of solid-phase extraction techniques.
authors.affiliation: Texas A&M University Agricultural Research and Extension Center, Overton 75684.
authors.forename: I J
authors.initials: IJ
authors.lastname: Pemberton
authors.forename: G R
authors.initials: GR
authors.lastname: Smith
authors.forename: T D
authors.initials: TD
authors.lastname: Forbes
authors.forename: C M
authors.initials: CM
authors.lastname: Hensarling
mesh_terms: D000045:Acacia / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D010627:Phenethylamines / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D010627:Phenethylamines