Sodium hydroxide

[Chip]

Sodium hydroxide

What are some good pharmaceutical brands of sodium hydroxide people are using that is pure and tested with ICP? I recently found a brand that was pretty dirty. Thanks

 

[Reefahholic]

Sodium hydroxide

What are some good pharmaceutical brands of sodium hydroxide people are using that is pure and tested with ICP? I recently found a brand that was pretty dirty. Thanks

What size tank is this being dosed on?

 

[Chip]

600 gallons.

 

[Chip]

What size tank is this being dosed on?

600 gallons

 

[Randy Holmes-Farley Verified Community Expert]

I do not see a reason to look too hard for pharma (USP) grade, and there's no a priori reason to assume pharma grade has higher purity standard than food grade, which is readily available. the tests are a little different, but neither is clearly better than the other for a reef tank, IMO:

Sodium Hydroxide USP NF Grade Specifications​

Identification— A solution (1 in 25) responds to the tests for Sodium.
Insoluble substances and organic matter— A solution (1 in 20) is complete, clear, and colorless to slightly colored.
Potassium— Acidify 5 mL of a solution (1 in 20) with 6 N acetic acid, then add 5 drops of sodium cobalt nitrite TS: no precipitate is formed.
Heavy metals— the limit is 0.003%.

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Sodium Hydroxide FCC Food Grade​

REQUIREMENTS
Identification: A 1:25 aqueous solution gives positive tests for Sodium.
Assay: Not less than 95.0% and not more than 100.5% of total alkali, calculated as NaOH.
Arsenic: Not more than 3 mg/kg.
Carbonate: (as Na2CO3) Not more than 3.0%.
Insoluble Substances and Organic Matter: Passes test.
Lead: Not more than 2 mg/kg.
Mercury: Not more than 0.1 mg/kg.

 

[Chip]

I do not see a reason to look too hard for pharma (USP) grade, and there's no a priori reason to assume pharma grade has higher purity standard than food grade, which is readily available. the tests are a little different, but neither is clearly better than the other for a reef tank, IMO:

Sodium Hydroxide USP NF Grade Specifications​

Identification— A solution (1 in 25) responds to the tests for Sodium.
Insoluble substances and organic matter— A solution (1 in 20) is complete, clear, and colorless to slightly colored.
Potassium— Acidify 5 mL of a solution (1 in 20) with 6 N acetic acid, then add 5 drops of sodium cobalt nitrite TS: no precipitate is formed.
Heavy metals— the limit is 0.003%.

---

Sodium Hydroxide FCC Food Grade​

REQUIREMENTS
Identification: A 1:25 aqueous solution gives positive tests for Sodium.
Assay: Not less than 95.0% and not more than 100.5% of total alkali, calculated as NaOH.
Arsenic: Not more than 3 mg/kg.
Carbonate: (as Na2CO3) Not more than 3.0%.
Insoluble Substances and Organic Matter: Passes test.
Lead: Not more than 2 mg/kg.
Mercury: Not more than 0.1 mg/kg.

Thanks for the info. But can you recommended a clean brand that works good and tested? A group of us reefers in my area used a product called Belle Chemical Sodium Hydroxide says 100% Hydroxide Food Grade. and all are ICP test tested with 4 high levels of metal. and we all had bad side effects.
Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the info. But can you recommended a clean brand that works good and tested? A group of us reefers in my area used a product called Belle Chemical Sodium Hydroxide says 100% Hydroxide Food Grade. and all are ICP test tested with 4 high levels of metal. and we all had bad side effects.
Thanks

I've never seen any full ICP testing of sodium hydroxide.

What exactly did you detect? it would not be surprising to detect all sorts of metals in it. Pharma grade (USP) allows up to 30 ppm heavy metals in the solid.

The question is what metals at what levels, and then look to see what effect those levels would have once diluted into an aquarium at doses one would actually use.

 

[Chip]

I've never seen any full ICP testing of sodium hydroxide.

What exactly did you detect? it would not be surprising to detect all sorts of metals in it. Pharma grade (USP) allows up to 30 ppm heavy metals in the solid.

The question is what metals at what levels, and then look to see what effect those levels would have once diluted into an aquarium at doses one would actually use.

Yes, It was not a ICP on the Hydroxide itself but on the tank water. Mostly Bromine, boron, barium. This is one of my worst ICP test.
lab.atiaquaristik.com/share/2160fdeff30ea54851d0

I've never seen any full ICP testing of sodium hydroxide.

What exactly did you detect? it would not be surprising to detect all sorts of metals in it. Pharma grade (USP) allows up to 30 ppm heavy metals in the solid.

The question is what metals at what levels, and then look to see what effect those levels would have once diluted into an aquarium at doses one would actually use.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, It was not a ICP on the Hydroxide itself but on the tank water. Mostly Bromine, boron, barium. This is one of my worst ICP test.
lab.atiaquaristik.com/share/2160fdeff30ea54851d0

Well, I cannot know where any chemical in the water came from, but I do not think any you listed is a tox problem.

The high borate will interfere with alk testing a bit.