Light Weight Evaporation Vessel for the Determination of Dissolved Solids

The determination of dissolved solids has long been a key parameter for water quality measurements. Water having high dissolved solids content could be unsuitable for use in industry. Water with concentrations greater than 500 mg/L usually ranks very low on a taste scale and can produce particularly adverse reactions amongst those who are not native to that water source. The test generally consists of evaporation in a tared dish of a known filtered volume of the water with subsequent weighing of the residue. These dishes need to be stable at the temperatures used as well as nonreactive to the matrix of the sample. Traditionally these dishes have been made of borosilicate glass, porcelain, or platinum. The difficulty often presented by these traditional materials is the weight difference between the container and the mass of residue produced. Most methods limit the mass of residue to be between 2.5 and 200 mg. They further require that the measured mass be reproducible to ± 0.5 mg. With such a large percentage of the mass being contributed by the dish the analyst is often confronted by unnecessarily long and drawn out testing sequences. The development of a lighter weight evaporation container will be discussed.