Sampling, Preservation and Storage Procedure of Water Sample

Sampling Procedure

1. Collect water samples for microbiological analysis in clean and sterilized nonreactive borosilicate glass or polypropylene bottles.
2. Neutralize the chlorinated water sampled by adding 1% sterile sodium thiosulphate solution.
3. Open the sampling port/tap fully and allow the water to drain for validated time to remove the contamination in the pipeline.
4. Adjust the flow to avoid splashing, open the sampling bottle and hold it at the base.
5. While sampling does not contaminate the inner surface of stopper or cap and neck of bottle. Do not touch the edge of the sample container.

6. Fill the required volume and replace the cap immediately.
7. Samples for Bacterial endotoxin test should be collected in depyrogenated glass bottle.
8. Collect a quantity of water samples required for chemical testing in non-reactive borosilicate glass or plastic bottles that have been cleaned and rinsed carefully and given a final rinse with Purified water.
9. Before sampling for chemical tests rinses the bottle with the same sample for at least 3 times, fill the bottle completely without leaving any space for air and replace the cap immediately.
10. For TOC tests Collect representative sample in cleaned dried glass containers Take care to avoid contamination of the sample with organic substances. Sampling container must be completely filled to the top without leaving any headspace.
11. Leave about 1% air space in the bottle sufficient to facilitate mixing by shaking before examination.

Preservation and Storage

1. It is recommended that samples should be analyzed immediately and storage should be avoided.
2. For TOC samples that can not be tested within 2 hours from the time of sampling, the sample is acidified to pH lower than 2 by adding 2 M hydrochloric acid.
3. For Microbiological testing analyze the samples within 6 hrs of sampling.
4. Refrigerate (2 to 8°C) the samples until testing is commenced.
5. Allow the samples to reach ambient temperature prior to testing.
6. Agitate samples for uniform distribution before testing.

Related: Validation Protocol for Hold Time Study of Collected Water Samples