Testing for the presence of soluble salts

The following test procedure is for the qualitative analysis, that is, the presence or the absence of soluble salts. For quantitative analysis (i.e., the amount) of soluble salts, refer to “Section 3.2 Determination of Soluble Salts” in Clifton’s Methods For Characterizing Adobe Building Materials.

Apparatus

• Minimum of 20 grams
• Salt test strips (Nitrate, Chloride, Sulfate)
• Deionized water

Sample Preparation
• Sieve sample through the 200 μm (No.10) sieve.
• Weigh and record the mass to the nearest 0.1g.

Procedure

  1. Soak 10g of the soil in 10 mL of deionized water for three hours to bring any soluble salts into solution. The solution may be heated on a hot plate (low heat) to facilitate the dissolution process.
  2. Immerse test strips into the solution and observe for color changes in the indicators on the strips