Some spattering of the sample into the watch glass does occur near dryness

The dissolved solid signifies towards any salts, minerals, metals, anions, or cations dissolved in water. The TDS (total dissolved solids) include inorganic salts, like magnesium, calcium, potassium, bicarbonates, sodium, sulfates, and chlorides, and certain small concentrations of organic matter, which are dissolved in water.

In the given case, the reported TDS will be very low, as the mass of the spattered sample was not returned and the weight of the sample is then influenced.