double distilled water

Where exceptionally high purity water is required, double distilled water is used.

Colonic and faecal water were prepared by reconstituting freeze dried samples with double distilled water to respectively 20% and 35% dry weight, to mimic the conditions in the proximal and distal colon.

Although formaldehyde and PFA were used in papers as listed in Table 1 and formaldehyde solutions may have been obtained from commercial sources, for our study a formaldehyde aqueous stock solution was prepared by dissolving 20 g of PFA powder in 90 ml of double distilled water.