RAPID MULTIRESIDUE SCREEN FOR ALKALOIDS IN PLANT-MATERIAL AND BIOLOGICAL SAMPLES

A multiresidue screen for the quantitative and qualitative determinati on of alkaloids in plant material, animal ingesta, tissue, and biologi cal fluid is described. The alkaloids were extracted with 5% ethanol i n ethyl acetate (v/v) after the addition of aqueous NaOH. The organic extract was cleaned up by partitioning with 0.5 N HCl. The aqueous pha se was made alkaline; the alkaloids were retained on a polymeric C-18 minicolumn and subsequently eluted with ethyl acetate. The concentrate d extract was analyzed quantitatively by GC/NPD. The alkaloids coniine , nicotine, atropine, retrorsine, solanidine, and strychnine were test ed to measure the performance of the method. Fortifications at 10 and 1 mu g/g of the six model alkaloids in alfalfa hay, bovine rumen conte nt, liver, urine, and serum were prepared. The method recovered the si x alkaloids in the range of 113-82% at the 10 mu g/g level and 113-72% at the 1 mu g/g level. Qualitative screening methods using a modified commercial TLC system and GC/MS were developed. Theoretical detection limits for qualitative screening ranged from 0.2 to 1.0 mu g/g, while theoretical detection limits for GC/NPD ranged from 0.025 to 0.2 mu g /g for the compounds studied using a nominal 5 g sample. The method wa s used successfully in a diagnostic case to identify lupine alkaloids in rumen contents.