Operation and methodology of an alanine ion-selective electrode dosimetric system: I. Electrode characteristics and data analysis

Abstract

A new electrochemical technique for high-dose dosimetry, employing an ion-selective electrode (ISE), consists of measuring the ammonia content of an aqueous sample after dissolving irradiated solid α-alanine. The operational principles, readout procedure, as well as data analysis are presented here and discussed. For direct calibrations, a modified Nernst equation produces the best fit to the experimental data. Time stability of the response parameters is shown to be very good. The background reading varies linearly with alanine concentration in the sample. The temperature coefficient of the readout system may be +1.3 mV C −1 (+4% C −1), so a thermostatic isolated set-up is recommended. The electrode response time is 1–3 min, depending on the concentration level.