What is the appropriate holding time for nitrate, if the sample is chlorinated and not acidified?

The appropriate holding time for nitrate samples that are chlorinated and not acidified is 14 days. This timeframe is essential because the integrity of nitrate samples can diminish over time due to various factors such as biological activity, chemical reactions, or degradation.

For non-acidified samples, chlorination can help preserve the sample temporarily by inhibiting biological activity that could otherwise alter nitrate levels. However, it is important to analyze the samples within the 14-day period to ensure accurate measurements. Beyond this timeframe, the reliability of the data may be compromised, leading to potentially inaccurate assessments of nitrate concentrations.

In the context of water quality monitoring and regulatory compliance, adhering to proper holding times is crucial for obtaining valid results that inform public health and environmental decisions. Thus, 14 days is established as the standard holding time for such samples in water quality testing.