2540 B. total solids dried at 103-105
1.General Discussion
a. principle: A well-mixed sample is evaporated in a weighed dish and dried to constant weight in an over at 103 to 105 C. the increase in weigth over that of the empty dish represents the total solids. the results may not represent the weight of actuar dis-solved and suspended solids in wastewater samples (see above).
b. interferences: highly mineralized water with a significant concentration of calcium, magnesium, chloride, and/or sulfate maybe hygroscopic and require prolonged drying, proper desiccation, and rapid weithing. exclude large, floating particles or submerged agglomerates of nonhomogeneous materials from the sample if it is determined that their inclusion is not desired in the final result. disperse visible floating oil and grease with a blender before with-drawing a sample portion for analysis. because excessive residue in the dish may form a water-trapping crust, limit sample to no more than 200 mg residue (see 2540A.2)