Method for the determination of veratridine and cevadine, major components of the natural insecticide sabadilla, in lettuce and cucumbers

Sabadilla, an insecticide widely used by organic farmers, can be separated into live of its components (veratridine, cevadine, cevine, cevacine, and sabadine) by high-performance liquid chromatography (HPLC) and detected by atmospheric pressure chemical ionization liquid chromatography mass spectrometry (APCI/LCMS). Using APCI/LCMS in the selected ion monitoring mode as the determinative step, an analytical method has been developed for the detection and quantitation of the two largest sabadilla components, veratridine and cevadine, in lettuce and cucumbers spiked with veratrine. The insecticides are extracted with acetonitrile/water, and the extract is cleaned up by solid phase extraction (SPE) on a C-18 cartridge. The limits of detection (calculated at a signal to noise ratio of 10 to 1) of veratridine and cevadine in cucumbers and lettuce are 1-2 ppb, and the recoveries range from 74% to 101%.