After the water sample is filtered and dried at a certain temperature, the solid residue obtained is called total dissolved solids, including non-volatile soluble salts, organic matter and insoluble particles that can pass through the filter, etc. The drying temperature of 105℃ is generally used, but the drying temperature of 180℃ cannot completely remove the water of crystallization contained in the salts in the high mineralization water sample. Drying temperature is generally used 105 ℃, but 105 ℃ drying temperature can not completely remove the high mineralization of water samples of salts contained in the water of crystallization, the use of 180 ℃ drying temperature, you can get more accurate results. When the total dissolved solids in the water sample contains a large amount of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, due to these compounds have a strong moisture absorption so that the weighing can not reach a constant weight, at this time the water sample can be improved by adding an appropriate amount of sodium carbonate solution.
Operation method
Experiments for the determination of total dissolved solids
Principle
After the water sample is filtered and dried at a certain temperature, the solid residue obtained is called total dissolved solids, including non-volatile soluble salts, organic matter and insoluble particles that can pass through the filter, etc. The drying temperature of 105℃ is generally used, but the drying temperature of 180℃ cannot completely remove the water of crystallization contained in the salts in the high mineralization water sample. Drying temperature is generally used 105 ℃, but 105 ℃ drying temperature can not completely remove the high mineralization of water samples of salts contained in the water of crystallization, the use of 180 ℃ drying temperature, you can get more accurate results. When the total dissolved solids in the water sample contains a large amount of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, due to these compounds have a strong moisture absorption so that the weighing can not reach a constant weight, at this time the water sample can be improved by adding an appropriate amount of sodium carbonate solution.
Materials and Instruments
Sodium carbonate solution Move 1. Instruments For more product details, please visit Aladdin Scientific website.
Analytical balance Water bath Electrothermal constant temperature drying oven Porcelain evaporating dish Dryer Silica gel as desiccant Medium-speed quantitative filter paper Filter wax Filter wax filter
(1) Analytical balance with a sensitivity of one ten-thousandth of a gram
(2) Water bath
(3) Electrothermal constant temperature drying oven
(4) Porcelain evaporating dish, 100ml
(5) Desiccator, with silica gel as desiccant
(6) Medium-speed quantitative filter paper or filter wax and the corresponding filter.
2. Reagents
1% sodium carbonate solution, weigh 10g anhydrous carbonic acid, dissolve in pure water, dilute to 1000ml.
3. Operation steps
(1) Dry the total dissolved solids at 105°C
(2) Wash the evaporating dish, put it in the oven at 105°C for 30 min, remove it, and put it in the desiccator to cool.
(3) Weigh the mass on an analytical balance, bake again, weigh until constant weight, and the difference between the 2 weighings is not more than 0.0004g.
(4) The evaporating dish is placed on the water soluble pot to evaporate, the evaporating dish is moved to 105 ℃ oven, removed after 1 hour, placed in the desiccator, 30min, weighing.
(5) Put the weighed evaporating dish into (105℃) oven again for 30min, and then put it into the desiccator for 30min, and weigh it until constant weight.
4. Calculation 