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DI Water versus Purified Water, USP

Has there been any studies performed to test Deionized ultra filtered water versus the standards for Purified water, USP. If so..how can I obtain the information?

Tracie H Sharp
- Owings Mills, Maryland, USA
2003

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2003

Tracie,

I would go to the source. Look up a major manufacturer of Lab DI equipment in a scientific catalogue like Fisher or VWR or? Write the manufacturer a nice Email asking for the information. A word of caution, there are several levels or TYPEs on DI water, so you need to know which one you want to compare to.

Generally speaking, USP grade water, Purified, is referring to a grade of medical water with minimum specifications listed in the US Pharmocia. Forgive the spelling. I would not expect that it would be as demanding as DI water specifications in the total cation and anion removal BUT it would be very interested in the level of selected cations and that it was very well sterilized-IE: no microscopic bad things growing in it.

James Watts
- Navarre, Florida

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USP grade is produced by distillation processes, and as such, is pyrogen and bacteriologically sanitized. Deionized water, which is slightly purer regarding ionic contaminants, is not considered pyrogen free. Ultrafiltration, which will remove 99.99% of possible pyrogens, is not the same thing as distillation, and thus, the 2 are different specifications meant for different uses.

Tom Baker
wastewater treatment specialist - Warminster, Pennsylvania
2003