Dosing Micro Amounts

[WhatCouldGoWrong71]

I am currently dosing between .04 and .08 ML daily of Chromium, Cobalt, Iron, Selenium, Vanadium and Iodide. My understanding is 1 drop = .03 ML. I ordered dropper bottles, however, I really want to get everything on dosers. Is there a standard practice where I could take say RODI or fresh salt water and mix a months worth? For example:

30 days x .08 ML dose = 2.4ML
30 days x 5 ML = 150 ML
SUM = 152.4ML
Daily dose = 5.08

What would I mix with those elements if this were possible? Thanks and good morning!

 

[Randy Holmes-Farley]

The concern with highly diluted trace elements is that some of them may air oxidize into other forms. Whether that is a true problem or not varies by the element.

Iodide becoming iodate, for example, may not be desirable.

But in the absence of having a micropipette to dose small amounts, I would serially dilute the stick solutions rather than use uncalibrated drop sizes, which are variable.

I would dilute then with ro/di water.

heres what I’d do, for example:


If you want to dose 0.08 mL if the stock solution.

Add 1 mL of the stock solution to 9 mL of ro/di.

Then you can dose 0.8 mL.

 

[Dan_P]

The concern with highly diluted trace elements is that some of them may air oxidize into other forms. Whether that is a true problem or not varies by the element.

Does the increased chance of oxidation come from a higher oxygen to element ratio when highly diluted?

 

[Randy Holmes-Farley]

Does the increased chance of oxidation come from a higher oxygen to element ratio when highly diluted?

Yes. If there’s a lot of iodide and a little O2, only a small fraction of the iodide can be oxidized to iodate before the O2 is used up. If there is just a little iodide and the same amount of O2 as in the previous example, then it can all be converted before the O2 runs out.

 

[Dan_P]

Yes. If there’s a lot of iodide and a little O2, only a small fraction of the iodide can be oxidized to iodate before the O2 is used up. If there is just a little iodide and the same amount of O2 as in the previous example, then it can all be converted before the O2 runs out.

Got it, reactant limitation in the bottle but not in a diluted solution preserves the oxidation state.

In the aquarium and ocean, is it the extreme dilution of the elements (slow reaction rate, maybe chelation too) that prevents/limits trace element oxidation?

 

[Dan_P]

Yes. If there’s a lot of iodide and a little O2, only a small fraction of the iodide can be oxidized to iodate before the O2 is used up. If there is just a little iodide and the same amount of O2 as in the previous example, then it can all be converted before the O2 runs out.

Oxidations could be affected by pH. Might adjusting the pH of the diluted solution be useful? Adding a chelating agent? Or best of all, use the gas sprayed into an opened bottle of wine to prevent oxidation.

 

[Randy Holmes-Farley]

Got it, reactant limitation in the bottle but not in a diluted solution preserves the oxidation state.

In the aquarium and ocean, is it the extreme dilution of the elements (slow reaction rate, maybe chelation too) that prevents/limits trace element oxidation?

Additives are sometimes the forms present in the ocean for solubility in the bottle reasons (ferrous iron additives for example). The forms in the ocean also constantly get shuffled about by different organisms acting on them.

 

[Randy Holmes-Farley]

Oxidations could be affected by pH. Might adjusting the pH of the diluted solution be useful? Adding a chelating agent? Or best of all, use the gas sprayed into an opened bottle of wine to prevent oxidation.

Those sorts of things can help, and to be honest, it’s not something that I even know is a substantial problem. Just something I worry about with dilution.

 

[Dan_P]

Those sorts of things can help, and to be honest, it’s not something that I even know is a substantial problem. Just something I worry about with dilution.

Quick, thought.

Would monitoring the ORP of an aerated trace element solution give us a sense of how sensitive oxidation is for such a mixture? This might raise more questions than answer but it’s the sort of thing @taricha would be good at sorting through. I imagine he might have already looked at the iodide to iodate conversion with ORP.

 

[Randy Holmes-Farley]

Quick, thought.

Would monitoring the ORP of an aerated trace element solution give us a sense of how sensitive oxidation is for such a mixture? This might raise more questions than answer but it’s the sort of thing @taricha would be good at sorting through. I imagine he might have already looked at the iodide to iodate conversion with ORP.

It certainly my will work for ferrous vs ferric iron, but I’m not sure whether iodate is active in terms of measuring ORP.

 

[taricha]

Quick, thought.

Would monitoring the ORP of an aerated trace element solution give us a sense of how sensitive oxidation is for such a mixture? This might raise more questions than answer but it’s the sort of thing @taricha would be good at sorting through. I imagine he might have already looked at the iodide to iodate conversion with ORP.

Interesting. I have some Red Sea Trace Parts a b c d. Part C is the one with iron, manganese Etc and other Trace metals of high interest.
Would be interesting to check a new bottle ORP vs my bottles that are year+ old.
I never checked to see if saltwater with 0.06ppm iodine has a different ORP if its added as iodide vs iodate.

 

[Dan_P]

Interesting. I have some Red Sea Trace Parts a b c d. Part C is the one with iron, manganese Etc and other Trace metals of high interest.
Would be interesting to check a new bottle ORP vs my bottles that are year+ old.
I never checked to see if saltwater with 0.06ppm iodine has a different ORP if its added as iodide vs iodate.

I have my doubt ps about whether ORP tells us much in highly diluted solutions of trace elements. Maybe we need to look at much higher concentrations to get a signal that might me useful to mess around with. The iodide to iodate chemistry might have to be monitored at stock solution concentrations or higher.

 

[Randy Holmes-Farley]

I think ORP would say a lot, though like pH, it is buffered against changes.

But aeration will raise ORP in those solutions.

 

[WhatCouldGoWrong71]

The concern with highly diluted trace elements is that some of them may air oxidize into other forms. Whether that is a true problem or not varies by the element.

Iodide becoming iodate, for example, may not be desirable.

But in the absence of having a micropipette to dose small amounts, I would serially dilute the stick solutions rather than use uncalibrated drop sizes, which are variable.

I would dilute then with ro/di water.

heres what I’d do, for example:


If you want to dose 0.08 mL if the stock solution.

Add 1 mL of the stock solution to 9 mL of ro/di.

Then you can dose 0.8 mL.

@Randy Holmes-Farley So with the above can I assume what I have copied below as far as mixing it to 100ML for slightly larger and more manageable auto dosing?

 

[WhatCouldGoWrong71]

bump

 

[taricha]

@Randy Holmes-Farley So with the above can I assume what I have copied below as far as mixing it to 100ML for slightly larger and more manageable auto dosing?

If I'm reading this correctly, thats not right. It looks like you're saying instead of dosing .08 of the original stock, you could do 1ml of the stock plus 9ml of distilled and dose 0.8 of the new solution, which is correct.
But the next line looks like you are saying you could do 10ml of the stock and 90ml of distilled which is still the same 1/10 dilution, but then you want to dose 8 mL of it. That would be 10 times the amount.

Instead do 1ml original stock + 99mL distilled.
Then dosing 8ml of that solution is the same as dosing 0.08ml of the original stock.
(Assuming nothing weird happens by diluting so much).

 

[WhatCouldGoWrong71]

If I'm reading this correctly, thats not right. It looks like you're saying instead of dosing .08 of the original stock, you could do 1ml of the stock plus 9ml of distilled and dose 0.8 of the new solution, which is correct.
But the next line looks like you are saying you could do 10ml of the stock and 90ml of distilled which is still the same 1/10 dilution, but then you want to dose 8 mL of it. That would be 10 times the amount.

Instead do 1ml original stock + 99mL distilled.
Then dosing 8ml of that solution is the same as dosing 0.08ml of the original stock.
(Assuming nothing weird happens by diluting so much).

Thank you so much.