Calculation of Total Dissolved Solids (TDS) of given water sample.
Apparatus:
Oven, desiccators, filter paper, pipettes.
Procedure:
* Heat clean dish for 1hour in an oven
* Store in desiccators and weigh immediately before use.
* Stir the sample and pipette a measured volume onto a glass fiber filter.
* Wash with three successive 10ml volumes of reagent grade water,Allow complete drainage between washings and continue suction for about 3 min after filtration.
* Collect the filtrate in the weighed dish and dry for atleast 1 hr in the oven at 180⁰C
* Cool in desiccators to balance temperature and weigh.
* Repeat cycle of drying, cooling, desiccating & weighing until a constant Weight is obtained.
Calculation:Total Dissolved Solids, mg /lit = (A-B) x1000 / Sample volume,ml
Where:
A = weight of dried residue + dish
B = weight of empty dish