How long should samples be preserved before analysis when dealing with volatile compounds?

When dealing with volatile compounds, preserving samples promptly is crucial to ensure that the results of the analysis are accurate and representative of the original sample. The correct answer involves analyzing samples within 24 hours provided they are chilled. This is because many volatile compounds are prone to evaporation and degradation if they are left at room temperature for extended periods. Chilling the samples helps minimize these effects by slowing down the chemical processes, thus preserving the integrity of the volatile compounds until analysis can be conducted.

If samples are not analyzed within this time frame or if they are kept at room temperature, there is a significant risk that the concentration of the volatile compounds will decrease or change, leading to unreliable results. Therefore, adhering to the guideline of staining samples within 24 hours when chilled strikes a balance between preserving the integrity of the volatiles while allowing enough time for transportation and preparation prior to analytical testing.