A well mixed sample is filtered through a standard glass filter and the filtrate is evaporated to dryness in a weighed dish and dried constant weight at 180OC. The increase in the dish weight represents the total dissolved solids.
· Evaporating dishes (100 ml capacity)
· Weighing balance
· Measuring cylinders
· Heat clean dish to 103OC to 105OC for 1 hour. Store and cool dish in desiccators until needed. Weigh immediately before use.
· Shake the water sample very well and add 100 ml into filtration device that is having glass filter on it. Apply vacuum and filter out 100 ml of sample.
· Collect the filtrate, in to evaporating dish.
· Put the dish into an oven at 105OC for overnight.
· Next day take out it from the oven and cool in tin desiccators dish would be having dried residues in it.
· Measure the weight of evaporating dish.
· Put the data or the pre weight and post weight of the dish in the following equation and calculate the amount of total solids present in the sample.
mg total solids/L = (A-B) x1000
mL of sample
Where, A = post weight of dish (weight of dried residues + dish)
B= pre weight (weight of dish, mg)