DPD test sample keeps turning pink

[red-beard]

I've noticed that if I leave the sample alone after the test, it starts to turn pink. I add more R-0871 and it turns clear. This takes several minutes. On the sample I am testing right now, I have given it 10 minutes. And so far, I've had to put in 7 more drops to keep it clear. On this sample, I have not yet put in R-0003. I have noticed this occurring after the CC test as well.

 

[Donldson]

Once the sample has turned clear the test is done. If left sitting the sample reacts with oxygen and turns pink again. This is normal and not a part of the test.

 

[red-beard]

OK