Checking for chlorate

[dangerousamateur]

Well, i've got a 2kg bag of perchlorate here. Wich is very very lumpy. I've never had that with perchlorate bevore, little lumps yes but this one has rock hard chunks.

Maybe it's KClO3....?

 

Whats the best method to test stuff for chlorate content?

[Mumbles]

If you think it's fully chlorate mixing about 50/50 with sugar and adding a drop of sulfuric acid will tell you for sure. If it lights on fire, it's chlorate, if it does little to nothing it's perchlorate. There are other spot tests, but that is probably the easiest.

[Potassiumchlorate]

Potassium perchlorate can be extremely hard caked as well.

[50AE]

Both can cake hard if pure. Caking is characteristic for many chemicals.

[dangerousamateur]

Thanks, i'll try it with acid. Do I need 95% or is 38% car battery stuff sufficient?

 

Potassium perchlorate can be extremely hard caked as well.

Well - if it's not - does that mean there is some kind of anticake involved? Is Anticake rather common?

Edited January 1, 2012 by dangerousamateur

[Potassiumchlorate]

It depends on the chemical dealer, but some % of SiO₂ is rather common.

[dan999ification]

my perc is hard to break up from almost like rocks to needing mutlipe screenings to get it fine again the mesh is small but it is bound/caked hard, but all pieces come out of the hdpe tub no prob leading me to believe that it went in the same not caked while it was inside

i understand the worry and i would test if your not sure.

has anyone had perc come as loose powder and then cake on its own or do you think the caking is down to milling extensively?

free flowing perc is not as pure with anti caking agents such as cabosil added.[ fraction of a percent]

 

dan.

[dangerousamateur]

I did the acid test and nothing happened.

 

Now let's imagine there are only 5% Chlorate in there. Is there some easy way to detect that?

In the best case without the need for rather uncommon chemicals...

[pyrojig]

I did the acid test and nothing happened.

 

Now let's imagine there are only 5% Chlorate in there. Is there some easy way to detect that?

In the best case without the need for rather uncommon chemicals...

 

Swedes blog shows a great process to indicate the % of chlorate .v.s perch in a batch of perch.

http://www.amateurpyro.com/forums/blog/2/entry-56-perchlorate-cleansing-success/

Edited January 2, 2012 by pyrojig

[Bonny]

I did the acid test and nothing happened.

 

Now let's imagine there are only 5% Chlorate in there. Is there some easy way to detect that?

In the best case without the need for rather uncommon chemicals...

 

Swede's blog is a great resource and the procedures are excellent and proven. The testing indicator he used "NPAA" is difficult to find, but detects to far greater accuracy than 5% - more likely into the PPM range IIRC.

 

IF you have 5% chlorate in your perc, then I wouldn't even consider it for use as perc, but more likely as chlorate. You could clean the perc you have by recrystallizing and washing a couple of times.

[pdfbq]

Take 1 gram Indigo carmine (NPPA alsmost impossible to buy, IC is easy)

dissolve this in 100ml H2O (can also be 1000ml, cant remember that but its not so important)

Take 1ml of HCl 30% (5% probably will work as well).

Put some drops of the Indigo carmine sol in this HCl solution till its blue but leave it a bit transparent.

 

Now dissolve some of your xClO4 in H20

Drip this in yout IC HCl solution

 

With a tiny bit of chlorate it will turn yellow.

 

When it stays blue its OK.

 

You can test the test by adding the tiniest of tiny bit of chlorate you can find to your blue perc solution. Immediate color change should occur.

Edited January 4, 2012 by pdfbq

[WSM]

Take 1 gram Indigo carmine (NPPA alsmost impossible to buy, IC is easy)

dissolve this in 100ml H2O (can also be 1000ml, cant remember that but its not so important)

Take 1ml of HCl 30% (5% probably will work as well).

Put some drops of the Indigo carmine sol in this HCl solution till its blue but leave it a bit transparent.

Now dissolve some of your xClO4 in H20

Drip this in yout IC HCl solution

With a tiny bit of chlorate it will turn yellow.

When it stays blue its OK.

You can test the test by adding the tiniest of tiny bit of chlorate you can find to your blue perc solution. Immediate color change should occur.

 

The texts say 0.02 g indigo carmine per 100 ml water and also treat the test solution with saturated sodium sulfite solution as well as the 3M HCl (25.8 ml reagent HCl diluted to 100 ml). This is a very sensitive test for chlorate and can tell if ppm are there, if done right.

 

1 gram in 100 ml water is 50 times too much according to the textbook test, and even 5 times too much per liter of water.

 

Indigo carmine is a good test reagent for chlorate and has been largely overlooked in these posts, lately. I plan to use it as well as the N-phenylanthranilic acid test.

 

WSM

Edited January 19, 2012 by WSM

[WSM]

The texts say 0.02 g indigo carmine per 100 ml water and also treat the test solution with saturated sodium sulfite solution as well as the 3M HCl (25.8 ml reagent HCl diluted to 100 ml). This is a very sensitive test for chlorate and can tell if ppm are there, if done right.

1 gram in 100 ml water is 50 times too much according to the textbook test, and even 5 times too much per liter of water.

Indigo carmine is a good test reagent for chlorate and has been largely overlooked in these posts, lately. I plan to use it as well as the N-phenylanthranilic acid test.

WSM

 

I decided to put my actions where my mouth was and mixed up some indigo carmine solution, 0.02% so I could prove my faith in the classic spot test. I still have to make up some saturated sodium sulfite solution which is about 6.8g/10ml H₂O at 20^oC. The problem with sodium sulfite solution is oxygen needs to be excluded or the sulfite converts to sulfate (from 2Na₂SO₃ + O₂ --> 2Na₂SO₄), so I'll keep a small amount in a plastic dropper bottle and squeeze out any air above the liquid (and hope this helps). I will also make up some 3M HCl as described before. If reagent grade HCl is difficult or impossible to obtain, 3M HCl can be made up using 31.45% muriatic acid (pool acid) by adding 31ml acid to enough distilled H₂O to yield 100ml.

 

 

To make up 500 ml of 0.02% solution, I added 0.10g of indigo carmine powder to the full measure of distilled water in the volumetric flask shown above. I don't know if the solution is stabile, but if it is, I just made a lifetime supply .

 

The weather is rainy outside today so I may just get to make up my other test reagents and run some spot tests !

 

 

More later...

 

WSM

[WSM]

I decided to put my actions where my mouth was and mixed up some indigo carmine solution, 0.02% so I could prove my faith in the classic spot test. I still have to make up some saturated sodium sulfite solution which is about 6.8g/10ml H₂O at 20^oC. The problem with sodium sulfite solution is oxygen needs to be excluded or the sulfite converts to sulfate (from 2Na₂SO₃ + O₂ --> 2Na₂SO₄), so I'll keep a small amount in a plastic dropper bottle and squeeze out any air above the liquid (and hope this helps). I will also make up some 3M HCl as described before. If reagent grade HCl is difficult or impossible to obtain, 3M HCl can be made up using 31.45% muriatic acid (pool acid) by adding 31ml acid to enough distilled H₂O to yield 100ml.

To make up 500 ml of 0.02% solution, I added 0.10g of indigo carmine powder to the full measure of distilled water in the volumetric flask shown above. I don't know if the solution is stabile, but if it is, I just made a lifetime supply .

The weather is rainy outside today so I may just get to make up my other test reagents and run some spot tests !

More later...

WSM

 

Okay, so I made up some sodium sulfite solution and 3M HCl and tested the reagents on a spot plate. I took a miniscule scraping from a safety match and put it in one dimple and added a drop of distilled water to each of two dimples (one for a control). Next I added a drop of the indigo carmine solution and sodium sulfite solution to each spot and then a drop of HCl to each spot.

 

The results? As expected, the spot with the match particle turned clear (because of the presence of chlorate) while the control stayed blue. No heating or large volumes of reagents required and a simple spot test worked just fine. It's more sensitive than other tests I've done and if the mixed reagents are stabile, will be my preferred method of testing for chlorate (though I still have more testing to do).

 

More, yet to come...

 

WSM

Edited January 23, 2012 by WSM

[pdfbq]

Cool WSM. I was too lazy look up for the right amounts but 50 times too much is a bit over kill indeed . Anyway, the idea was you end up with a transparent fluid.

 

I never used the Sodium Sulfite, just used 30% HCl solution (non reagent grade) and got perfect results.

 

There are some pictures out here of my tests in the perchlorate thread but that thread is becoming a bit big...

[WSM]

Cool WSM. I was too lazy look up for the right amounts but 50 times too much is a bit over kill indeed . Anyway, the idea was you end up with a transparent fluid.

I never used the Sodium Sulfite, just used 30% HCl solution (non reagent grade) and got perfect results.

There are some pictures out here of my tests in the perchlorate thread but that thread is becoming a bit big...

 

You mean I don't need that stinky sodium sulfite (smells like cat whizz if it gets on your hands ) ?!! Actually, I think it helps prevent interference from other things in the mix, but for just the plain salt (I know that label is around here somewhere... ), I see your point.

 

Thanks pdfbq, I'll have to give it a try.

 

WSM

[WSM]

You mean I don't need that stinky sodium sulfite (smells like cat whizz if it gets on your hands ) ?!! Actually, I think it helps prevent interference from other things in the mix, but for just the plain salt (I know that label is around here somewhere... ), I see your point.

Thanks pdfbq, I'll have to give it a try.

WSM

 

Hi pdfbq,

 

I tried the method you mentioned on a small bit of composition scraped from the head of a safety match and didn't get the chlorate reaction until I added the sodium sulfite solution. Several things are known to interfer with the test and one possibility is dichromate in some safety matches. I believe the sulfite helps counter some of these interfering ions and makes the test more specific to chlorate.

 

I still need to try your method on plain KClO₃ and see the difference.

 

later...

 

Okay, I did try it (on some cell liquor) and it worked (sparingly) but worked much better with the sodium sulfite solution than without it. From what I see so far, I'll have to stick to the method using that smelly sulfite solution. I should be smart and wear nitrile gloves when performing these spot tests so I don't get my hands stinky, too!

 

I believe the indigo carmine spot test is extremely sensitive and can detect chlorate down to less than one ppm. The jury is still out on the N-phenylanthranilic acid spot test that Swede developed. It's simpler to perform but I need to see if it's sensitivity even comes close to the indigo test.

 

More later...

 

WSM

Edited February 5, 2012 by WSM

[pdfbq]

Hi WSM,

 

I'm no chemist so don't understand really whats going on down there..

 

The thing that puzzles me though is that I use sodium metabisulphite to destroy my chlorate leftovers. I think sodium sulfite can be used for the same reason and both are related.

Maybe my tests went well because I used the metabisulphite to destroy my chlorate and then test for it,

Edited February 5, 2012 by pdfbq

[WSM]

Hi WSM,

I'm no chemist so don't understand really whats going on down there..

The thing that puzzles me though is that I use sodium metabisulphite to destroy my chlorate leftovers. I think sodium sulfite can be used for the same reason and both are related.

Maybe my tests went well because I used the metabisulphite to destroy my chlorate and then test for it,

 

Hi pfdbq,

 

I'm not sure, but as to the metabisulfite acting to replace the sulfite(?)... maybe. A quick scan of the Merck Index tells me the difference between them (besides structure and formula) is the solution of the sulfite is alkaline and the solution of the metabisulfite is acid. How this plays in your analysis I can't say (I don't know), but it's possible residual components of the metabisulfite are there if you haven't removed them by washing , drying and dissolving the chlorate product before testing it.

 

Maybe you should try your test before as well as after destroying the chlorate contaminant with metabisulfite, and see if there's a difference? Let me know how that turns out.

 

WSM

[pdfbq]

This was my original post about IC

 

Of course I test before, and after and, commercial perc and my clean perc with the smallest amount of chlorate i could find.

 

I think I'm fine here

[Mumbles]

Sodium sulfite is used in the lab as a reducing agent. It specifically is used to remove stuff like chalcogenides and halogens. I could see a little sodium sulfite around being potentially used to remove any traces of free chlorine from the HCl or chlorate solution. It would seem to me that the reaction revolves around the indigo carmine being oxidized. Besides chlorine, it could possibly also destroy lesser chlorine oxides, as you said before to make it more sensitive to chlorates.

[WSM]

Sodium sulfite is used in the lab as a reducing agent. It specifically is used to remove stuff like chalcogenides and halogens. I could see a little sodium sulfite around being potentially used to remove any traces of free chlorine from the HCl or chlorate solution. It would seem to me that the reaction revolves around the indigo carmine being oxidized. Besides chlorine, it could possibly also destroy lesser chlorine oxides, as you said before to make it more sensitive to chlorates.

 

True. The classic test described by Korenman states: "Oxidizing agents such as permanganate and hypochlorite decolorize indigo carmine in the absence of sulfite.", so if you're testing the mother liquor without using the sulfite it'll probably always indicate chlorate, whether it's there or not. Better to use the sulfite and be sure.

 

WSM