1837
Anal. Chem. 1983,55, 1837-1839
1.0 cm
I C
-
t
_7_
--J
D
Flgure 1. Vertical section of the jacketed cell for low-temperature electrochemistry: (A) JIS 1'56 O-ring (Viton), (e) Pyrex glass cup, (C and D) inlet and outlet of tlhe coolant.
small heater (5 Q) was immersed in the LN2 Dewar. The voltage applied to the heater was 10-20 V ac and a solid-state relay was used to switch it. The switching noise generated from the relay was negligibly small with the aid of a zero-crossing detector incorporated in the relay. In order to regulate the cell temperature, the temperature of the cooling gas was monitored at the end of the cooling gas line with a temperature sensor AD590F (Analog Devices, MA). The above lineup provided a very simple cooling system because it required only a voltage comparator and the relay as circuits regulating the cell temperature. A copper-constantan thermocouple was inserted into the cell in order to obtain the exact temperature of the sample solution. The reference electrode used was Ag/Ag+ (10 mM) 0.1 M tetrabutylammonium perchlorate.
+
to Cell
RESULTS AND DISCUSSION
t
When the temperature was
