Tunze CA test kit.

[fishypets]

Was wondering if adding the titration in the tube without out the dropping tip would affect the accuracy of the test? Seems like every time I use the tip I have a air bubble that seems bigger than the norm.

Thanks in advance

 

[rvitko]

I would use the tip, I don't see anyway to get an accurate result without it. I would do like nurses do before they inject you, tip it upright, tap the syringe so the air goes to the tip and then push the air out and reimmerse it to fill it the remainder.

 

[alrha]

wouldnt the air not make a difference as it is just the volume of the tip?
if you push the syringe down by .1mL, then that is the amount of titrant added, regardless of the air in the syringe.

 

[rvitko]

You know, I have never been clear on that to be honest. I have often wondered if the tip shouldn't be placed on after ward or if the instructions compensate for the initial volume of the tip. Habib at Salifert would be in a position to give a definitive answer at least for his products and we could assume it is similar. Either way we are talking about an error that would change our Calcium result by maybe 20 ppm so I wouldn't be overly concerned.

 

[alrha]

FWIW, Habib instructs users to disregard the air when using his kits.
I believe it should be the same for any similar kit.