Determination of Dissolved Solids (By Weight)

GB1576—2001

A4 Determination of Dissolved Solids (by weight)

A4.1 Overview

A4.1.1 Dissolved solids refer to the residue obtained by evaporating and drying the filtrate after separating and suspending solids.

A4.2 Apparatus

A4.2.1 Water bath or 400mL beaker.

A4.2.2 100-200mL porcelain evaporating dishes.

A4.3 Determination Method

A4.3.1 Take a certain amount of filtered and thoroughly shaken clear water sample (the volume of the water sample should be such that the weight of the evaporated residue is approximately 100mg), and successively pour it into evaporating dishes that have been dried to constant weight. Evaporate to dryness in a water bath.

Note: To prevent impurities from falling into the evaporating dish during the evaporation and drying process and affecting the test results, a glass tripod must be placed on the evaporating dish and a watch glass must be placed on top.

A4.3.2 Transfer the evaporated sample along with the evaporating dish to an oven at 105-110℃ and dry for 2 hours. A4.3.3 Remove the evaporating dish and place it in a desiccator to cool to room temperature, then weigh it quickly.

A4.3.4 Dry under the same conditions for 0.5 hours, cool, and weigh. Repeat this process until a constant weight is achieved.

A4.3.5 The dissolved solids content (RG) is calculated according to formula (A2):

Where: G1—total weight of evaporated residue and evaporating dish, mg;

G2—weight of evaporating dish, mg;

V—volume of water sample, mL.