Rejuvenating Cobalt Chloride Test Strips
CoCl2 test strips are cheap, but if you are in the middle of an experiment and find your entire supply has turned pink because their vial
turns out to not be airtight, this procedure might be useful. Also, if your strips are stuck together, here is a method to separate them quickly and
without wrinkling them.
First, please put on your gloves! Then set a clean beaker (150ml is a good size) on a ceramic gauze 3-6 cm above an alcohol lamp flame. Other heat
sources may work, but it must be a <b>gentle</b> heat. You should always be able to hold the beaker in your hand without burning yourself.
If you get too much heat you may scorch the strips and ruin them.
If your strips are stuck together, break them down into blocks no thicker than about 3-4 mm. Then hold a block loosely between the thumbs and
forefingers of both hands and bend it into a U-shape. The ends of the block will slide into wedge shapes as the strips on the inside of the U stick
out more than those on the outside. Now, pinch the block tightly at both ends. Finally, straighten the U back to as straight as possible. You will see
what was the inner strip will become straight but each strip behind it will be more and more curved, thus peeling each strip off of its neighbors.
Toss these strips (should be no more than about 10-15 at a time) into the warm beaker. The parts of the strips touching the glass should start to turn
robins' egg blue almost instantly. Pick up the beaker and shake it to get all parts of the strips to turn blue.
That's it! Repeat this with the rest of your strips and then store them in a <b>truly</b> airtight container.
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