Moisture free DPD powder storage

[JesseWV]

I was reading that the DPD powder needs to be kept dark, cool and dry. The dark and cool parts are easy enough. I live in a moderately high humidity region so I'm pretty sure an amount of moisture gets into the container every time I open it.

I'm thinking about adding some balls of silica gel desiccant to the powder. This would remove the moisture but would it cause any other problems? The balls are a little smaller than a BB and I'm sure I could avoid scooping them up in the spoon.

I might even be able to get one of those tiny drum looking things that has all the silica get inside out of an old medicine bottle and see if that fits in the container. However I did notice that the container in the TF-100 is rather small compared to the container Taylor uses for the same 10g of DPD powder. So why is the Taylor container is so much bigger? Do they already have a desiccant built into the container?

 

[CaOCl2]

Do they already have a desiccant built into the container?

Yes, the container (Taylor part 2629) is lined with dissecant.

 

[duraleigh]

However, it is the experience of forum members here and another forum that exposure to SOME humidity is harmless even though it turns the powder dark. I had some I used for four years and was almost charcoal yet it was as effective as new, fresh powder.

I have yet to get a report of ineffective powder....dark for sure but not ineffective.

 

[JesseWV]

However, it is the experience of forum members here and another forum that exposure to SOME humidity is harmless even though it turns the powder dark. I had some I used for four years and was almost charcoal yet it was as effective as new, fresh powder.

I have yet to get a report of ineffective powder....dark for sure but not ineffective.

So as long as it still produces a pink solution it's doing it's job, yes?

I was mainly concerned because the DPD powder I have already seems to have a decent amount of white clumps in it. They almost look like something different than the crystals. They also never dissolve. Are these clumps still the same substance or something else?

 

[duraleigh]

Yeah, mine always clumps, too, but it has no affect on the test.

Just like you implied, the sole purpose of the powder is to turn the solution pink/red. Once that occurs, it is the job of R-0871 (liquid drops) to neutralize the pink and determine the amount of chlorine available

 

[Flotsam]

... well - here's another question I had (clumping powder) - guess I can strike this one off my list!

Thanks all !!!

As a follow-up - I suppose that grinding it into a fine powder in a petri dish would be Okay? (I'll need to get rid of the salt peter residue first I guess).

 

[257WbyMag]

I just break mine up with the little spoon. I don't get to involved with it since all I need it to do is turn my sample pink.