Procedures
1. Sample preparation
1.1 Preparation of drying container
Place container in the drying oven at 100 ± 5°C until constant weight (1 - 2 h). Cool
in a desiccator for about 30 min and weigh (W1). For liquid or semisolid sample, prepare drying
container with 15 - 20 g acid washed sand and a stirring rod.