How should samples for VOC analysis be stored?

For volatile organic compounds (VOCs) analysis, the preservation and storage of samples are crucial to maintaining their integrity. Storing samples at temperatures between -5 to 4 degrees Celsius is recommended because colder temperatures help reduce the volatilization of these compounds. By minimizing the risk of evaporation and chemical changes, this temperature range preserves the composition of the sample until analysis can be performed.

In contrast, room temperature can lead to the degradation and loss of VOCs due to their inherent volatility. Extreme temperatures, including the range listed in one of the options, can still pose a risk for certain compounds that may be sensitive even in that cooler spectrum. Direct sunlight can also cause photo-degradation or chemical reactions in organic compounds, leading to inaccurate results. Therefore, storing samples specifically at -5 to 4 degrees Celsius provides optimal conditions for preserving these types of samples for accurate analysis.