Total organic material or Total Organic Matter (TOM) illustrates the total organic matter content of a body of water comprising dissolved organic matter, suspended (particulate) and colloids. TOM analysis principle nearly equal to the principle of COD analysis is based on the fact that almost all of the organic material can be oxidized by using compounds of potassium permanganate or potassium dichromate.
Oxidizer used in the determination of TOM is KMnO4, acidified with concentrated H2SO4 and boiled while. TOM content measurement can be done by titration.
Tool :
titration device
Thermometers
Erlenmeyer
Hot plate
Pipette volume
Pipette Mohr
Material :
6 N H2SO4
0.01 N KMnO4
H2C2O4 0.01 N
Ways of working :
o pipette 25 ml water sample, is inserted into the erlenmeyer.
o Add 0.5 mL of H2SO4, some Teter 0.01 N KMnO4 to a pink berwarba bit so that all low-level organic compound is oxidized to a high level.
o Pipette 10 ml of 0.01 N KMnO4 thereto. The color of the solution will be red.
o The solution is boiled, note the hour. The color of the solution will be younger, simmer for 10 minutes and then removed.
o Lower the temperature to 80 ° C, add 10 ml of 0.01 N oxalic acid with a special pipette. The solution will become clear in excess oxalate.
o In a temperature of 70-80 ºC titasi solution with 0.01 N KMnO4 up to pink.
Calculation:
TOM (mg / l) = (10 + a) b – (10 xc) 31.6 x 1000
Where :
a = titration of KMnO4
b = N KMnO4
c = NH2C2O4 0.1 N
d = sample water (mL)