When transporting samples to the laboratory for analysis, it is important to preserve representative samples with what?

Preserving representative samples during transport to the laboratory is crucial for ensuring the integrity and accuracy of the analysis results. Utilizing ice is an effective method to maintain the temperature of the samples, thereby inhibiting the growth of microorganisms and chemical reactions that could alter the sample's composition. Keeping samples cool helps to slow down these processes and allows for a more reliable analysis once the samples reach the laboratory.

In contrast, other methods such as using air may fail to provide the necessary temperature control, whereas sodium chloride and dry ice can introduce their own chemical components that might interfere with the sample's characteristics or affect the results of certain tests. Therefore, using ice is typically the most standard practice for preserving the quality of wastewater samples during transport.