FLOW-INJECTION POTENTIOMETRIC DETERMINATION OF HARMINE AND HARMALINE HALLUCINOGENS

Flow injection analysis (FIA) systems incorporating potentiometric sensors for harmine and harmaline hallucinogens are described. The sensors are based on the use of harmine and harmaline tetraphenylborate or reineckate as electroactive compounds dispersed in plasticized PVC matrix. Laboratory-build flow-through sandwich cell equipped with silver disk coated with the sensing material is used as a detector in a low dispersion FIA system. The detector exhibits fast and linear response over the concentration range 10(-2)-10(-6) M harmine or harmaline with a detection limit of 2 mu g/mL (for 100 mu L samples). Operational pH ranges from 3 to 8, sampling rate is 80 per hour and the precision is typically +/- 0.6%. Recovery and reproducibility data agree fairly well with those obtained by gas-liquid chromatography.