Evaluation of Gravimetric Methods for Dissoluble Matter in Extracts of Environmental Samples

A number of gravimetric methods were evaluated for the determination of dissolved matter in solvent extracts of combustion samples. The methods described included thermogravimetric analysis, weighing after evaporation under nitrogen, and a microscale evaporation method developed in this study. A well characterized combustion sample, known to consist primarily of alkylated bicyclic and tricyclic aromatic compounds, served as a reference material. Results for the three methods are presented and compared. Although the thermogravimetric analyzer was found to be accurate and versatile, a good compromise between cost, time and accuracy was provided by the microscale evaporation method.