Convert PDTA ferric sodium salt to ammonium salt, is it possible?

Josaw98 · Dec 5, 2024

I found a supply of ferric EDTA and PDTA at a fertilizer store, I want to use them to make C41 and E6 bleach but when I looked at the SDS I saw that they are sodium salts. Is there a way to convert them to ammonium salts?

koraks · Dec 6, 2024

Realistically, and to the best of my knowledge: no.

You may be able to make a functional bleach with the sodium species. It may be very slow, but if you're patient and allow for a sufficiently long bleach time, this may not necessarily be a problem. IDK, you could try. I can't say if the bleach will go to completion and there will be no retained silver at all. Again, you'd have to try. E6 will be more challenging than C41.

Alternatively, you could make a much faster, very effective and very cheap bleach with plain old ferricyanide. Nobody knows what that does for the archival stability of the negatives, but the bleach will work in principle, at least on C41 film and I assume on E6 just the same.

But in all honesty, your best bet would be to just bite the bullet and acquire some commercially-made bleach (e.g. Kodak Flexicolor). While it may seem very expensive, it keeps almost forever, it can be regenerated (to an extent) by periodically adding some ammonium bromide and aerating the bleach, and the cost per roll turns out to be low enough to not worry about it.

I've done a lot of DIY chemistry, also for color, but my conclusion remains for now that DIY-ing a color bleach just isn't worth it at a consumer-level scale.

lamerko · Dec 6, 2024

koraks said:
I've done a lot of DIY chemistry, also for color, but my conclusion remains for now that DIY-ing a color bleach just isn't worth it at a consumer-level scale.

Unfortunately, E-6 bleach is not commercially available.

koraks · Dec 6, 2024

lamerko said:
Unfortunately, E-6 bleach is not commercially available.

Then how do labs manage this? They obtain the chemistry as well.

FujiFilm current products:

Any distributor or retailer can order these from Fujifilm.
The Bleach Replenisher does indeed have a high list price if you check e.g. dupli.co.uk (who have it on stock). However, that's for 20L volume, so you could part it out and sell what you don't need to others, and as said it's economical on a per-roll basis due to the high capacity.

koraks · Dec 6, 2024

FYI this is presently the entire E6 workflow chemistry kit as available from Fuji Hunt in Europe:

PRO6 DEVELOPERS
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
944637	Pro6 First Developer Starter	6 x 1 L
944645	Pro6 First Developer Replenisher	4 L	20 L
976977	Pro6 Universal Color Developer Starter	6 x 1 L
944694	Pro6 Color Developer Replenisher Kit	20 L

PRO6 REVERSAL BATHS
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
991323	Pro6 Reversal 2 Bath & Replenisher	1 L	20 L

PRO6 PRE-BLEACHES
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
979070	Pro6 Pre-Bleach 2 & Replenisher	2 x 2 L	2 x 20 L

PRO6 BLEACHES
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
818369	Pro6 Bleach Starter	6 x 1 L
818377	Pro6 Bleach Replenisher	20 L cube	40 L

FIXERS
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
919407	Super Unilec Fixer	4 L	40L

PRO6 FINAL RINSE
CATN°	PRODUCT NAME	CONC	SIZE TO MAKE
979088	Pro6 Final Rinse	6 x 0,2 L	6 x 20 L

Note the volumes; these are evidently not intended for small tank/home processing, but they can be used in this application if you want.

lamerko · Dec 6, 2024

Yes, I've seen it - I've spoken to three distributors - it seems like there's just no chance. Either it's not being produced, or it's on special order. There's just no place to buy it...

koraks · Dec 6, 2024

Like I said, dupli.co.uk has it on stock. Also, even though it's special order, you could ask your retailer to order it for you. They will order it specially for you - which is what "special order" infers anyway.

The product numbers above were provided to me last month by Fuji Hunt. Surely they manufacture the stuff.

lamerko · Dec 6, 2024

koraks said:
Like I said, dupli.co.uk has it on stock. Also, even though it's special order, you could ask your retailer to order it for you. They will order it specially for you - which is what "special order" infers anyway.

The product numbers above were provided to me last month by Fuji Hunt. Surely they manufacture the stuff.

Unfortunately, I get a firm refusal to order. I'm currently looking at the dupli website - quite unpleasant. In addition to the large volume of chemistry, there is a lack of starting chemistry and pre-bleaching. But delivery from UK will also be a problem. I'll look elsewhere.

koraks · Dec 6, 2024

First, you state that the product isn't available. I explain it is and give an example of a company that even has it on stock. Then the story is that it's no good and that other firms refused selling to you. I don't think this is about problems with the availability of this product. I stated the volume clearly earlier on, also. This problem seems to be more about you not knowing how to order materials and/or not willing to face the realities of doing so.

Here are two retailers who may be able to help you:
fotofilmfabriek.nl
easymedal.de
Neither list the E6 bleach or its starter on their websites. Both are capable of placing orders directly with FujiFilm. In the knowledge of what the product is (its volume and approx. sales price), I kindly ask you to not waste either of these guys' time by asking questions without intention to order. Both ship internationally (within the EU), but I nor anyone else can guarantee that they will ship to Bulgaria specifically and/or that you will like their offers. For small-scale use, there are E6 kits from a variety of manufacturers that I trust you know how and where to buy.

Good luck with your sourcing effort; let's now go back to the central questions in this thread.

Alan Johnson · Dec 6, 2024

Josaw98 said:
I found a supply of ferric EDTA and PDTA at a fertilizer store, I want to use them to make C41 and E6 bleach but when I looked at the SDS I saw that they are sodium salts. Is there a way to convert them to ammonium salts?

I think this task defeated the experts earlier:

Making EDTA from Na2-EDTA

For C41 and E6 bleach we need Ammonium Ferric EDTA, which is often not easily available, especially at a good price. The most easy to obtain EDTA compound is Na2-EDTA, since EDTA is frequently used as water softener and the Disodium salt is much more water soluble than the free acid. If we want...

www.photrio.com

Josaw98 · Dec 6, 2024

Alan Johnson said:
I think this task defeated the experts earlier:

Making EDTA from Na2-EDTA

For C41 and E6 bleach we need Ammonium Ferric EDTA, which is often not easily available, especially at a good price. The most easy to obtain EDTA compound is Na2-EDTA, since EDTA is frequently used as water softener and the Disodium salt is much more water soluble than the free acid. If we want...

www.photrio.com

Thanks! I read it a while ago and have already put it into practice with good results in E6 and C41. I haven't tested it, it should work, but since I saw those chemical products for sale, I thought maybe I can avoid precipitating and drying free acid EDTA.

Josaw98 · Dec 6, 2024

@koraks @lamerko I greatly appreciate your responses and participation in this thread.

I live in Mexico and here and throughout Latin America, Kodak and Fujifilm don't care about us. The few kits that can be obtained have high prices due to taxes.

I currently have a functional bleach formula for E6 thanks to what @Rudeofus has posted here.

For C41 I have used a formula that is also quite functional and economical that uses sodium persulfate as an oxidizing agent, however this formula uses a catalyst to accelerate the reaction, it consists of dipicolinic acid and ferric nitrate. What is happening? I ran out of dipicolinic acid and the only supplier I have for that is Sigma Merck, who will take a month to send me this.

Today I was walking down the street and I came across someone selling

koraks · Dec 6, 2024

Josaw98 said:
I live in Mexico and here and throughout Latin America, Kodak and Fujifilm don't care about us.

There's more in the world than FujiFilm. I offered Fuji as an example because that's what's generally available the easiest in Europe.
In the Americas including Mexico, my bet would be on Kodak/Photosys. Surely there's a way to get some of that chemistry hauled across the Mexican border, somehow. But I think I've offered that suggestion before to you.

Josaw98 said:
The few kits that can be obtained have high prices due to taxes.

Especially the E6 chemistry can be expensive because it's a low-volume product. It's probably not held on stock by most retailers because it barely sells anyway.

If you want to shoot color and you want low cost per frame, shoot digital. Color negative can be affordable especially if you use ECN2 film (as long as that remains available to us, at least). Slide film is relatively expensive.

I understand your desire to cut corners. I think it's a matter of experimenting and spending countless hours scourging sales databases and sending emails & making phone calls. Personally, I find I have only so much patience for that sort of thing and at some point would rather pick up a camera (any camera) and go out shoot some pictures. YMMV.

Josaw98 · Dec 6, 2024

I agree, always have to sacrifice something, money, time or energy, sometimes even all three. I will really consider how practical it is to buy a commercial kit. I also hope this thread will help lab enthusiasts experiment and generate an alternative and option to what already exists.

halfaman · Dec 6, 2024

lamerko said:
Yes, I've seen it - I've spoken to three distributors - it seems like there's just no chance. Either it's not being produced, or it's on special order. There's just no place to buy it...

Another possibilty is Bellini, they have 5 liter presentation of E6 bleach-replenisher.

E6 Bleach Replenisher - Bellini Foto

Bleach Replenisher specifically formulated for the E6 process at 38°C

www.bellinifoto.it

Ask them directly to place an order.

lamerko · Dec 11, 2024

halfaman said:
Another possibilty is Bellini, they have 5 liter presentation of E6 bleach-replenisher.

E6 Bleach Replenisher - Bellini Foto

Bleach Replenisher specifically formulated for the E6 process at 38°C

www.bellinifoto.it

Ask them directly to place an order.

It seemed like a good idea to write about my dramas - Bellini's solution seemed exactly what I needed.

Thanks a lot!

halfaman · Dec 11, 2024

lamerko said:
It seemed like a good idea to write about my dramas - Bellini's solution seemed exactly what I needed.

Thanks a lot!

Happy to help

Rudeofus · Dec 16, 2024

Josaw98 said:
For C41 I have used a formula that is also quite functional and economical that uses sodium persulfate as an oxidizing agent, however this formula uses a catalyst to accelerate the reaction, it consists of dipicolinic acid and ferric nitrate. What is happening? I ran out of dipicolinic acid and the only supplier I have for that is Sigma Merck, who will take a month to send me this.

If you ever run out of this very special bleach accelerator: there are recipes for persulfate&quinone bleaches around. I have those in the back of my head, but for my life can't find them anywhere, neither here on photrio, nor in my personal records. I'll keep searching.

The bleach itself is made from some bromide, Hydroquinone (which turns into Quinone, the actual bleaching agent, after 24 hours in this soup), Sodium Persulfate, some pH buffer and a trace of Copper Sulfate. These are all compounds, which should be trivially available to you.

Examples for such formulas are e.g. found in this patent.

Rudeofus · Dec 16, 2024

Josaw98 said:
I found a supply of ferric EDTA and PDTA at a fertilizer store, I want to use them to make C41 and E6 bleach but when I looked at the SDS I saw that they are sodium salts. Is there a way to convert them to ammonium salts?

To answer your original question: there are official E-6 bleach recipes out there, which are made from Ammonium Ferric EDTA and Potassium Bromide plus some other stuff. You can probably imagine, that you will get a very similar bleach with Sodium Ferric EDTA and Ammonium Bromide.

There are fixer patents out there, which claim little to no speed loss, if about 50% of the thiosulfate comes as sodium salt and the rest as ammonium salt. Therefore I don't expect Sodium Ferric EDTA plus Ammonium Bromide to be much slower than the 100% ammonium variety.

One more thing: sodium and potassium ions are not your friend in fixer. Therefore if you make your bleach from 50% sodium or potassium salts, make sure you have a decent wash between bleach and fixer step.

Josaw98 · Dec 18, 2024

Rudeofus said:
If you ever run out of this very special bleach accelerator: there are recipes for persulfate&quinone bleaches around. I have those in the back of my head, but for my life can't find them anywhere, neither here on photrio, nor in my personal records. I'll keep searching.

The bleach itself is made from some bromide, Hydroquinone (which turns into Quinone, the actual bleaching agent, after 24 hours in this soup), Sodium Persulfate, some pH buffer and a trace of Copper Sulfate. These are all compounds, which should be trivially available to you.

Examples for such formulas are e.g. found in this patent.

Well I left this thread while I was doing some tests, thanks for your participation, I have already seen the quinone bleach that you mention, I also saw that it is advisable to use copper sulphate in its anhydrous form to avoid washing, what I never knew is what type of solution to prepare to clean the film in case of using blue copper sulphate. Will it be with sodium bisulfite?

Josaw98 · Dec 18, 2024

Rudeofus said:
To answer your original question: there are official E-6 bleach recipes out there, which are made from Ammonium Ferric EDTA and Potassium Bromide plus some other stuff. You can probably imagine, that you will get a very similar bleach with Sodium Ferric EDTA and Ammonium Bromide.

There are fixer patents out there, which claim little to no speed loss, if about 50% of the thiosulfate comes as sodium salt and the rest as ammonium salt. Therefore I don't expect Sodium Ferric EDTA plus Ammonium Bromide to be much slower than the 100% ammonium variety.

One more thing: sodium and potassium ions are not your friend in fixer. Therefore if you make your bleach from 50% sodium or potassium salts, make sure you have a decent wash between bleach and fixer step.

regarding this i did the following: i bought a bag of sodium ferric EDTA and also a bag of PDTA, parentheses here the bag of DTPA is Sodium hydrogen ferric DTPA but lets start with the EDTA. i prepared a saturated solution of sodium ferric EDTA (100-110gr/L) to this i added 15gr of ammonium chloride and ammonia little by little until a pH of 5.8, it seems that by stoichiometry this makes EDTA ferric ammonium salt, but i am a newbie at this so any help is accepted. ah this solution i only added 80gr of ammonium bromide. i developed an E6 film using the formulas i am familiar with and used this bleach that i prepared. I am attaching a photo of the result:

Josaw98 · Dec 18, 2024

The bleaching time was 6 minutes. I monitored it every 2 minutes and at minute 4 you could already see that the bleach was working correctly.

Josaw98 · Dec 19, 2024

Regarding DTPA, something different happened, I prepared a saturated solution of Sodium hydrogen ferric DTPA and added 13g of Ammonium Chloride and Ammonia until reaching a pH of 5.8, then added 80g of Ammonium Bromide. A deep red solution with yellow hues was formed and much denser than the EDTA solution, it does not let light through. Even so, I tested it with C41 film directly after the developer, applying a previous stop bath with a pH higher than 4. And yes, it did bleach but it took about 5 minutes to perform a complete bleaching. Here is a photo of the results.

Josaw98 · Dec 19, 2024

I am hoping that the ammonium chloride is exchanging with the sodium, but it is very likely that nothing is happening and that I am just using 2 halogenated agents instead of one. I don't know, but I do know that it is working.

Josaw98 · Dec 19, 2024

I'm about to get 1.3 PDTA and be able to do the bleach that you suggested here on the forum @Rudeofus

Convert PDTA ferric sodium salt to ammonium salt, is it possible?

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