How should samples taken on a routine basis be preserved?

Preserving samples taken on a routine basis is crucial for maintaining their integrity and ensuring accurate analysis. Refrigeration is the recommended method for preserving samples because it slows down microbial activity and reduces biochemical reactions that could alter the sample's original state. By keeping samples at lower temperatures, typically around 4 degrees Celsius, the growth of bacteria and other organisms is inhibited, allowing for reliable assessment when the samples are analyzed.

Freezing is not ideal for all types of samples because it can cause the breakdown of compounds and may alter the physical or chemical properties of certain substances. Exposure to sunlight can lead to degradation of some samples, particularly those that are sensitive to light, while adding chemicals might not be appropriate for all scenarios, as it can introduce variables that affect test outcomes or create reactions that wouldn't occur in the natural sample. Therefore, refrigeration is the most effective and widely accepted method for preserving water samples in a way that results in minimal alteration before analysis.