エポキシ樹脂を膜材とした陰イオン選択性被覆線電極の検討

抄録

Coated-wire electrodes (CWEs) for anions (chloride, nitrite, nitrate, iodide, and perchlorate) were constructed by the use of epoxy resin as a material of electrode membrane. The CWEs consist of a copper wire and the polymer matrix membrane containing about 30 wt % of a liquid ion exchanger (60 wt % Aliquat 336 S in 1-decanol) which was coated on the whole surface of wire at (0.10.2) mm thickness. The sizes of the electrodes are apporoximately 1 mm o. d. of stick shape. The responses were Nernstian in the range of (5× 10^-54 × 10^-2) M anions for all constructed anion selective CWEs. The electrodes gave a rapid response time of a few second at the lower limit of the linear concentration range with the stability of ±2 mV. The CWEs have a long life (most of the electrodes are still functioning after 3 months' use) and can be stored in air (renewed calibration was required for some stored electrodes). The selectivity sequences of anions for the CWEs were apporoximately consistent with the Hofmeister's lyotropic anion series. The selectivity coefficients for each anion selective CWE on interfering anions were almost the same with those obtained by the liquid membrane electrodes having the same ion exchanger solution employed for the CWEs. Consequently, the polymer matrix membrane of the CWEs seems to be functioned according to the same mechanism as liquid membrane type electrodes