ABSTRACT
Plastic ion-selective membrane sensor analysis of the hydrophobic amine antimalarial mefloquine and related drugs in blood samples was investigated by D. W. Mendenhall et al. Problems associated with the blood concentration determination of such hydrophobic amines include glass adsorption, protein binding, and poor sensitivity by conventional detection methods. A selective ion-pair extraction was used for mefloquine isolation prior to plastic selective membrane sensor monitoring. Mefloquine alkylation with various relatively lipophilic alkyl produced derivatives detectable by the membrane sensor at much lower levels than the parent. The sensors were calibrated in cerebrospinal fluid solutions of constant ionic strength. The potential of ion-selective membrane sensor is directly related to the activity of hydrophobic cations in aqueous solutions, and response is Nernstian. Penicillin was applied to the cortical surface via a second micro-sensor by pressure ejection. The tip of this sensor was placed in the immediate vicinity of the recording sensor just above the cortical surface, which was covered by thermosta-bilized mineral oil.
