At what temperature are the organic portions of suspended solids determined by volatilization?

The correct choice for determining the organic portions of suspended solids by volatilization is 550 degrees Celsius. At this temperature, a significant portion of the organic matter within suspended solids volatilizes, allowing for an accurate assessment of the organic load in water samples. This process is part of various standard methods used in environmental analysis to quantify the organic content in solids.

The selection of this specific temperature is important because it ensures that the organic materials are sufficiently broken down without incinerating the inorganic materials, which could occur at higher temperatures. This balance is crucial for obtaining reliable results in environmental compliance and monitoring. Choosing this temperature helps in adhering to standardized methodologies, which contribute to the consistency and comparability of environmental data across different studies or reports.

The other temperatures listed do not align with the standard methods followed in environmental analysis for evaluating organic content in suspended solids. Lower temperatures might not fully volatilize the organic components, while higher temperatures risk altering or destroying the inorganic matrix, leading to inaccurate measurements.