EQUIPMENT

1. Analytical Balance capable of weighing 0.1 mg
2. Porcelain Evaporating Dishes, 50 mL
3. Desiccator
4. Muffle Furnace
5. Oven

PROCEDURE

1. Evaporation dish preparation.
   1. Volatile solids - Ignite a clean evaporation dish at 550 °C for 1 hour in a muffle furnace. Store in a desiccator until ready for use.
   2. Total Solids only - Place a clean evaporation dish in a 103-105 degrees C oven for 1 hour. Store in a desiccator until ready for use.
2. Total Solids
   1. Record the weight of an empty 50 mL evaporation dish to the nearest 0.1 mg.
   2. Add approximately 25 g of sample and record the weight of the dish plus wet sample to the nearest 0.1 mg.
   3. Place into a 103-105 °C oven overnight.
   4. Remove the sample from the oven and place it into a desiccator.
   5. After the sample reaches room temperature, record the weight of the dish plus dry sample to the nearest 0.1 mg.
3. Volatile Solids
   1. Place the sample obtained in 2e in a cold muffle furnace and ignite for 2 hours ad 550 °C.
   2. Remove the sample from the furnace and place in a desiccator.
   3. After the sample reaches room temperature, Record the weight of the dish plus the ignited sample.

CALCULATIONS

% Total Solids = (A - B) ÷ (C - B) × 100
% Volatile Solids = (A - D) ÷ (A - B) × 100

where:

A = Weight of dish plus dried sample to the nearest 0.1 mg.
B = Weight of the dish to the nearest 0.1 mg.
C = Weight of the dish plus wet sample to the nearest 0.1 mg.
D = Weight of the dish plus ignited sample to the nearest 0.1 mg.

REFERENCE

1. Total, Fixed, and Volatile Solids in Solid and Semisolid Samples, in Standard Methods for the examination of Water and Wastewater, 19th Edition, 1995, chapter 2, p 58.