Ultrapure Water Applications – Selection of Containers for Water Samples

The choice of material for the container holding the water sample is the primary issue in sample preservation.

1. Container Requirements

The following points must be considered when selecting the container material:

1.1 The container must not cause new contamination. Ordinary glass can leach elements such as sodium, calcium, magnesium, silicon, and boron when storing water samples. Glass containers should be avoided when measuring these substances to prevent new contamination.

1.2 The container walls should not absorb or adsorb certain analytes. Ordinary glass containers adsorb metals, while plastics such as polyethylene adsorb organic matter, phosphates, and oils. This should be considered when selecting the container material.

1.3 The container should not react with certain analytes. For example, when measuring fluoride, water samples cannot be stored in glass bottles because glass reacts with fluorides.