eutech-instruments cyanide epoxy User Manual

Cyanide Electrode 

 

Instruction Manual

 

 

4

 
3. 

Cyanide Standard, 1X10

-2

M. To prepare this solution from your own laboratory stock, add 

10 ml of ISA and about 500 ml of distilled water to a one liter volumetric flask. Add 0.49 
grams of dry, reagent-grade sodium cyanide, NaCN, to the solution and swirl the flask 
gently to dissolve the solid. Dilute to the mark with distilled water, cap, and upend the 
flask several times to thoroughly mix the contents. Store all standards in plastic bottles and 
prepare weekly. 

 
4. 

Cyanide Standard, 1,000 ppm. To prepare this solution from your own laboratory stock, 
add 10 ml of ISA and about 500 ml of distilled water to a one liter volumetric flask. Add 
1.88 grams of dry, reagent-grade NaCN and swirl the flask gently to dissolve the solid.  
Dilute to the mark with distilled water, cap, and upend the flask several times to 
thoroughly mix the contents. Store all standards in plastic bottles and prepare weekly. 

 
 

GENERAL PREPARATION 
 

 
Remove the rubber caps covering the electrode tips and the rubber insert covering the filling hole of 
the cyanide combination ion electrode or the reference electrode. Fill the reference electrode or the 
combination electrode with the filling solution shipped with the electrode to a level just below the 
fill hole. No preparation is required with a sealed reference electrode. Connect the electrodes to the 
proper terminals as recommended by the meter manufacturer. 
 

(Check electrodes each day) 
 

1. 

To a 150 ml beaker, add 100 ml of distilled water and 1 ml of 10M NaOH ISA.  Place the 
beaker on a magnetic stirrer and begin stirring at a constant rate. After assuring that the 
meter is in the millivolt mode, lower the electrode tips into the solution. 

 
2. 

Using a pipet, add 1 ml of 1.0X10

-2

M or 1,000 ppm standard to the beaker. When the 

reading is stable, record the mV reading. 

 
3. 

Using a pipet, add 10 ml of the same standard used above to the beaker. After the reading 
has stabilized, record the mV reading. 

   
4. 

The electrode is operating correctly if the mV potential has changed by 57±2 mV, 
assuming the solution temperature is between 20

o

 and 25

o

C. See the 

 

sections if the potential change is not within this range. 

 

Slope is defined as the change in potential observed when the concentration changes by a factor of 
10. 
 

(Check electrodes each day)