eutech-instruments bromide epoxy Manuel D’Utilisation

Instruction Manual 

 

Bromide Electrode 

 

6 

 
Bromide ions can be measured in units of moles/liter, parts/million, or any other convenient 
concentration unit.  Table 1 indicates some of the concentration units. 

    TABLE 1: Concentration Unit Conversion Factors 

 
            moles/liter  

ppm 

Br

-1

 

             1.0X10

-4

            

   8.0 

             1.0X10

-3

          

   

79.9 

             1.0X10

-2

           

799.0 

             1.0X10

-1

     

 

7,990.0 

 
 
MEASUREMENT PROCEDURE 

 
Direct measurement is a simple procedure for measuring a large number of samples. A single meter 
reading is all that is required for each sample. The ionic strength of samples and standards should 
be made the same by adjustment with ISA for all bromide solutions. The temperature of both 
sample solutions and of standard solutions should be the same. 
 

 

1. 

By serial dilution prepare three standard solutions from the 0.1M or 1,000 ppm standard. 
The resultant concentrations should be 10

-2

, 10

-3

, and 10

-4

M or 1,000, 100 and 10 ppm 

bromide standards. Add 2 ml of ISA to each 100 ml of standard.  Prepare standards with a 
composition similar to the samples if the samples have an ionic strength above 0.1M. 

 
2. 

Place the most dilute solution (1.0X10

-4

M or 10 ppm) in a 150 ml beaker on the magnetic 

stirrer and begin stirring at a constant rate. After assuring that the meter is in the mV mode, 
lower the electrode tips into the solution. When the reading has stabilized, record the mV 
reading. 

 
3. 

Place the mid-range solution (1.0X10

-3

M or 100 ppm) in a 150 ml beaker on the magnetic 

stirrer and begin stirring at a constant rate. After rinsing the electrodes in distilled water, 
blot dry and immerse the electrode tips in the solution. When the reading has stabilized, 
record the mV reading. 

 
4. 

Place the most concentrated solution (1.0X10

-2

M or 1,000 ppm) in a 150 ml beaker on the 

magnetic stirrer and begin stirring at a constant rate. After rinsing the electrodes in distilled 
water, blot dry and immerse the electrode tips in the solution. When the reading has 
stabilized, record the mV reading. 

 
5. 

Using semi-logarithmic graph paper, plot the mV reading (linear axis) against the 
concentration (log axis). Extrapolate the curve down to about 1.0X 10

-

5

M or l ppm. A 

typical calibration curve for bromide can be found in Figure 1.