Dpd Powder Shelf-Life

[mcw53]

What is the shelf-life of Taylor DPD Powder?

I'm needing to refill my suppy. Amato has this for $4.80/10g ($0.48/g) and $25.72/4oz ($0.23/g). The cost/use of the 4oz bottle is less than 1/2 that of the 10g bottle, but I am concerned about shelf-life as it will take me years to use the 4oz bottle. The 4oz bottle would be stored in ideal conditions and only opened to refill the bottle in my K-2006 test kit.

[quantumchromodynamics]

http://www.taylortechnologies.com/product_fliers/technical_bulletin.pdf

http://www.taylortechnologies.com/ChemistryTopicsCM.ASP?ContentID=26

[mcw53]

http://www.taylortechnologies.com/product_fliers/technical_bulletin.pdf

http://www.taylortechnologies.com/ChemistryTopicsCM.ASP?ContentID=26

Thanks. I am aware of Taylor's statement on shelf life and understand their point of view.

If kept dry, powders and crystals are very stable; acids are also long lived. Date of manufacture is not the controlling factor when it comes to shelf life—storage conditions are more important.

As a general precaution, replace all reagents more than one year old, or at the beginning of a new testing season.

Would it be unreasonable to expect a 2 or even 3 year shelf life for DPD Powder considering the storage conditions I stated in my original post?

[quantumchromodynamics]

I think that Taylor would be the best source of information about this.

If you have questions concerning reagent shelf life or storage, call the Taylor technical hotline, 800-TEST KIT (837-8548), Monday through Friday between 8:00 A.M. and 5 P.M. Eastern Time.

If you could call them and post what they say, that would be great.

[PaulR]

On another forum I remember reading somebody saying they had 2-year-old powder with no issues.

I also remember reading as long as the powder hasn't turned black, it should be okay.

--paulr

[quantumchromodynamics]

The reagent can be good for up to 3 years if it is stored under ideal conditions. The sign of a compromised reagent is that the reagent will become pink.