Testing with salifert titration test kits...hints?

[emanaresi]

Hey everyone. I have used the salifert titration test kits in the past, and just got some new ones for ca, alk, and mag.

Anyway, I have always wondered whether or not you can cheat these test a little bit. Meaning, if you know roughly where your levels are, can you squirt in a certain amount of the test fluid but stop a few drops short of where you expect it to be instead of going dripwise all of teh way through. From my very limited experience in chemistry, this would seem to work fine. I just wanted to see if anyone knew for sure?

 

[Subliminal]

Yeah, works fine for me. I only use their magnesium test kit, but I usually squirt darn near the whole thing into the tube, swish for a bit, then do the drip for the closeness at the end.

 

[emanaresi]

Yeah that is what I figured and what I have been reading (while a little confusing) seems to indicate that this is acceptable. Thanks for the feedback.

 

[mynd]

I am sure that i have used the salifert magnesium test kit in the past. Now I use the Red Sea Test kit. As long as you do not get air bubbles in the syringe it is quite accurate and after the first time very easy to use. There is not much waste either, which makes it a decent test.

 

[mladencovic]

Hey everyone. I have used the salifert titration test kits in the past, and just got some new ones for ca, alk, and mag.

Anyway, I have always wondered whether or not you can cheat these test a little bit. Meaning, if you know roughly where your levels are, can you squirt in a certain amount of the test fluid but stop a few drops short of where you expect it to be instead of going dripwise all of teh way through. From my very limited experience in chemistry, this would seem to work fine. I just wanted to see if anyone knew for sure?

For most of the tests this is OK (I do it for Ca, Alk and Mg) as long as you do not overshoot it you will be fine. For some tests (Sr for example), however, you need to do it slowly for two reasons - they require precise measurments in their intermediate steps, and some chemical reactions need more time to stabilise and you need to space the drops. If you need to know more deatils of how the titration works, drop me a note and I will describe it in more details.

...
As long as you do not get air bubbles in the syringe it is quite accurate and after the first time very easy to use. There is not much waste either, which makes it a decent test.
...

As a matter of fact you are supposed to get an air buble (one big at the top of syringe) in Salifert and other test kits that use the standard syringes. That is - if the buble comes only from the initial volume of the air from the "needle" part of the syringe, you are OK and the elimination of the air buble will not affect the results, specially if the the total amount administered is smaller then what the syringe is rated for.

 

[mynd]

You know that brings up a curious point. When I do the test I take off the dripper, insert the syringe and then I draw in the fluid.. Then I point it straight up and tap it a few times to get the air to the top and then I remove the air and draw in more fluid.

I guess the question here is does the test kit assume you are going to have air in the line at the back of the syringe making up for it with what is in the tip of the syringe or are you suppose to have no air in the syring at all. This is important cause this could be the difference of like 40ppm. Not a huge jump but some of us are anal like that.

What do you think?

 

[blange3]

I guess the question here is does the test kit assume you are going to have air in the line at the back of the syringe making up for it with what is in the tip of the syringe or are you suppose to have no air in the syring at all. This is important cause this could be the difference of like 40ppm. Not a huge jump but some of us are anal like that.

What do you think?

It does assume there will be air at the back end, it does metnion it in the instructions I have.

 

[mynd]

I actually just called redsea and they said and I quote " You must remove all air bubbles by thumping on the syringe just as if you were giving someone a shot " So the air in the syringe does not account for the fluid in the tip? " No, you must remove the air " ok thanks you.

From RedSea themselves. Good to know..

North America
Red Sea,
18125 Ammi Trail,
Houston, Texas 77060, USA.
Toll Free: 1-888-REDSEA9

 

[blange3]

I was referring to the Salifert, missed the Red Sea thing!

 

[Subliminal]

Basically, with the kit mentioned by the OP, it doesn't matter if there's air or not. As long as the air rises to the top and isn't being initially injected. You could have 1/2 the tube full of air, but if you don't actually get to the air bubble, the song will still remain the same.

 

[mladencovic]

Basically, with the kit mentioned by the OP, it doesn't matter if there's air or not. As long as the air rises to the top and isn't being initially injected. You could have 1/2 the tube full of air, but if you don't actually get to the air bubble, the song will still remain the same.

You are absolutely right. As long as only the fluid is escaping from the syringe, you are OK, no matter how much air is in the syringe. The amount of fluid released will correspond to the volume displacement in the syringe which you read from the markings. And this is regardless of which company's test kit you are using. Since many of these kits use plastic 1ml syringe with attached plastic "needle", assumption is that no liquid or air will be escaping through the joint.

Sorry mynd, but the person who gave you such instructions was either playing safe for inexperienced users (sometimes small amounts of air are sucked and remain in the "needle" if it was not properly submerged while drawing the reagent into the syringe) or simply did not understand anything about it. Again, removing all air will not hurt but is a waste of time.