How much water sample should be collected for preserved and transported analyses compared to regular analyses?

For preserved and transported analyses, the requirement is typically to collect at least two times the regular amount of water sample. This is important because preserved samples often need to be subsampled for different types of analyses or tests that may be performed later. Additionally, having a larger amount allows for more flexibility in preserving the sample appropriately, accommodating any losses that might occur during handling, transport, or changes in sample integrity over time.

This approach ensures that sufficient sample volume is available to perform all the required analyses without compromising the accuracy and reliability of the results. Proper sample preservation involves chemical treatments and may also require splitting the samples into different containers for distinct types of analysis, which can further necessitate a larger initial volume.

The other options suggest either equal to or less than double the volume, which may not provide enough sample for comprehensive testing, especially in scenarios requiring multiple analyses or where specific preservation protocols are involved.