Philippine National Standards for Drinking Water - LWUA

2.8.2 Changes caused by the growth of organisms may be greatly retarded by
keeping the sample in the dark and at a low temperature until it can be
analyzed.
2.8.3 It is necessary to keep the samples cool or refrigerated. Storage at a low
temperature (4 o C) is the best way to preserve most samples.
2.8.4 Add chemical preservatives to samples only as specified in specific
analytical methods. Suitable preservative that will not affect the results of
the analyses to be made must be selected.
The recommended sampling and preservation of sample according to parameters
for analysis are presented in Table 3. The list is by no means inclusive. It is clearly
impossible to prescribe absolute rules for the preservation of all possible changes.
Advice is included in the notes under the individual determination.
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