FLOW-INJECTION POTENTIOMETRIC DETERMINATION OF HARMINE AND HARMALINE HALLUCINOGENS

Flow injection analysis (FIA) systems incorporating potentiometric sen sors for harmine and harmaline hallucinogens are described. The sensor s are based on the use of harmine and harmaline tetraphenylborate or r eineckate as electroactive compounds dispersed in plasticized PVC matr ix. Laboratory-build flow-through sandwich cell equipped with silver d isk coated with the sensing material is used as a detector in a low di spersion FIA system. The detector exhibits fast and linear response ov er 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 r anges from 3 to 8, sampling rate is 80 per hour and the precision is t ypically +/- 0.6%. Recovery and reproducibility data agree fairly well with those obtained by gas-liquid chromatography.