Potentiometric Differential Microdetector With Interchange Solid Membranes Used in Flow Injection Analysis

Abstract

The construction and characteristics of two potentiometric differential microdetectors equipped with two similar ion-selective membranes are described. The two membranes used were of Ag ₂ S for Ag ^I and S ^{2 -} and CuS–Ag ₂ S for Cu ^II . The active volume of the measuring cell was about 3 µl. Calibration plots were linear, with almost theoretical slopes, down to 10 ^{- 6} mol dm ^{- 3} Ag ^I , 5 × 10 ^{- 6} mol dm ^{- 3} Cu ^II and 10 ^{- 5} mol dm ^{- 3} S ^{2 -} . The throughput was 40–60 samples h ^{- 1} depending on the sample. The errors in the determination of the above-mentioned ions were below 3.9%.