What is the purpose of using a preservative in water samples?

Using a preservative in water samples is essential to maintain the integrity of the samples until the analysis can be performed. Preservatives are designed to inhibit biological activity, prevent chemical changes, and reduce the breakdown of certain compounds that can occur after the sample has been collected. This stabilization ensures that the results of the analysis accurately reflect the water quality at the time of collection, rather than being skewed by any alterations that might take place during storage or transport.

When a sample is collected, microorganisms, temperature fluctuations, and exposure to light can all lead to changes in its composition. By applying the appropriate preservative, analysts can mitigate these effects and ensure reliable and valid results when the sample is eventually tested. This practice is crucial for conducting accurate water quality assessments and complying with regulatory standards.