TA test does not turn red (or any other color)

[coog61]

Using my TF Test kit for the first time. For the TA test, followed directions: water 25 ml, added two drops of R-0007 (mix), add 5 drops of R-0008 (mix) [water turns green] and then R-0009 one drop at a time (mixing between each). However, the water never changes from green. Test from PS and another kit shows the TA at ~80.

I am cleaning the tip between drop of the ..09. Also the drops seem very small (approx. half the size of typical droplets).

Any ideas? Do I need to mix for 20 sec between drops like for the CH test?

 

[PaulR]

The R-0009 drops ought to be about the same size as for any other reagent. If the drops are small you probably have the static buildup problem. Wipe the tip with a damp cloth between each drop (decrease the frequency if experience shows the drops are okay that way). If you still get really small drops, it's conceivable you have a defective tip.

The R-0009 works in a second or two, mixing time is not the problem.
--paulr

 

[CaOCl2]

If you mix say 3 drops of R-0008 and 3 drops of R-0009 together (no water), are you getting a red color?

 

[coog61]

If you mix say 3 drops of R-0008 and 3 drops of R-0009 together (no water), are you getting a red color?

yes, its red

 

[JasonLion]

This really sounds like the static buildup problem that PaulR mentioned causing you to not add enough titrant. Try doing the test again, wiping the dropper tip with a damp tissue at the start and after every three or four drops.

 

[coog61]

Yes, the static build up was the issue. Thanks.