Which of the following statements about sample storage preservation is true?

Refrigeration can indeed slow chemical activity, which is crucial for maintaining the integrity of water samples in water treatment and testing procedures. When samples are collected for analysis, their chemical composition can change over time due to biological activity and chemical reactions. By cooling the samples, the rate of these reactions is reduced, helping to preserve the original characteristics of the sample until analysis can be performed. Proper preservation is vital to ensure that the test results reflect the actual conditions of the water at the time of sampling.

On the other hand, storing samples at room temperature can allow for alterations in the water's chemical properties, which may yield inaccurate test results. Samples cannot be stored indefinitely; they have specific holding times depending on the type of analysis being conducted, which means that prolonged storage can compromise the sample integrity. Lastly, while some chemical preservatives may be used in certain cases, they are not universally applicable and are often subject to regulatory considerations, making their use not recommended in all situations.