At what temperature in Fahrenheit must samples be refrigerated?

Refrigeration of samples is crucial for preserving the integrity of water quality testing. The recommended temperature for refrigerating samples is typically around 39 degrees Fahrenheit. This temperature is cold enough to slow down biological activity and chemical reactions that could otherwise alter the sample's characteristics before analysis.

Keeping samples at this temperature ensures that the microbial life present in the water does not grow or die off significantly, which could lead to inaccurate test results. Additionally, it helps maintain the stability of certain parameters that could change with temperature variations.

While a temperature of 32 degrees Fahrenheit is the freezing point of water, it could lead to potential freezing of the samples, which is not advisable because it may damage the sample or alter its properties. The higher temperatures listed, such as 45 degrees and 50 degrees, are generally too warm for effective refrigeration, allowing for chemical and biological processes to occur that could compromise the reliability of the water testing results. Therefore, maintaining samples at 39 degrees Fahrenheit is the best practice for ensuring valid and accurate testing outcomes.