Will the real Mytol please stand up

[Andrew O'Neill]

Where does one easily source DTPA?

 

[Alan Johnson]

"easily" !
It's the way you tell em.

 

[Andrew O'Neill]

"easily" !
It's the way you tell em.

The place I source it doesn't carry it. I need to learn how to tell em, I guess...

 

[Rudeofus]

The place I source it doesn't carry it. I need to learn how to tell em, I guess...

That's the point. None of the places, which have that stuff in stock, will show it in their price lists. It's an "if you ask us, we may find it in our inventory" type product. I could never figure out, what kind of illegal activity could possibly be pursued with DTPA and ATMP, none of the chemists could ever tell me, but for some reason this type of product is never ever listed officially. It's also on average easier to get the sodium salt instead of the free acid, since salts are less scary to chem dealers and shipping companies than acids.

The best starting point would be chem suppliers, who either have their own assortment of packaged photographic products, or who are known to supply the companies who do.

 

[Andrew O'Neill]

That's the point. None of the places, which have that stuff in stock, will show it in their price lists. It's an "if you ask us, we may find it in our inventory" type product. I could never figure out, what kind of illegal activity could possibly be pursued with DTPA and ATMP, none of the chemists could ever tell me, but for some reason this type of product is never ever listed officially. It's also on average easier to get the sodium salt instead of the free acid, since salts are less scary to chem dealers and shipping companies than acids.

The best starting point would be chem suppliers, who either have their own assortment of packaged photographic products, or who are known to supply the companies who do.

Thank you the straight up answer.

 

[albada]

Yes, I am on it right now. Also, it's important to know, if the formula is asking for DTPA-Na5 1gram and not DTPA free acid as I thought at the beginning, maybe it's in fact DTPA-Na5 40% solution? @albada maybe can tell us more.

Here are what my notes say about the old name+formula and new name+formula of the sodium metaborate that XTOL specifies:

OLD: Sodium metaborate octahydrate, Na2B2O4*8H2O
NEW: Sodium metaborate tetrahydrate, NaBO2*4H2O
Other names: Sodium metaborate 8 Mol, Kodalk
CAS: 10555-76-7 (MW = 137.88)

BTW, the XTOL patent specifies 1 g of DTPA*5Na for its "Dry Formulation", so that weight is for the dry powder and not a solution.
For your reference, here is a screenshot of the formula in the patent:

Mark

 

[Milpool]

Here are what my notes say about the old name+formula and new name+formula of the sodium metaborate that XTOL specifies:

OLD: Sodium metaborate octahydrate, Na2B2O4*8H2O
NEW: Sodium metaborate tetrahydrate, NaBO2*4H2O
Other names: Sodium metaborate 8 Mol, Kodalk
CAS: 10555-76-7 (MW = 137.88)

BTW, the XTOL patent specifies 1 g of DTPA*5Na for its "Dry Formulation", so that weight is for the dry powder and not a solution.
For your reference, here is a screenshot of the formula in the patent:

View attachment 361663

Mark

Incidentally a decade or more ago (I can’t remember exactly when but I did discuss it with Dick Dickerson at the time) the metaborate was substituted with borax in commercially packaged XTOL.

 

[Alain Deloc]

Here are what my notes say about the old name+formula and new name+formula of the sodium metaborate that XTOL specifies:

OLD: Sodium metaborate octahydrate, Na2B2O4*8H2O
NEW: Sodium metaborate tetrahydrate, NaBO2*4H2O
Other names: Sodium metaborate 8 Mol, Kodalk
CAS: 10555-76-7 (MW = 137.88)

BTW, the XTOL patent specifies 1 g of DTPA*5Na for its "Dry Formulation", so that weight is for the dry powder and not a solution.
For your reference, here is a screenshot of the formula in the patent:

View attachment 361663

Mark

Thanks, man! I thought it should be a dry powder, not solution. I also found @Nikola Dulgiarov post about metaborate substitution and finally I adapted the formula like bellow, after I substituted also the sodium ascorbate with ascorbic acid (highly available at low prices where I live)

Water ........................... 750ml
Sodium sulfite ........ 89.65 g
DTPA-Na5 dry .................. 1g || DTPA-Na5 40% sol .... 2.5 g
Borax ............................... 2.8 g
Sodium Hydroxide .. 1.59 g
Ascorbic acid .......... 10.67 g
Dimezone-S ................. 0.2 g
Water to 1L

 

[albada]

Thanks, man! I thought it should be a dry powder, not solution. I also found @Nikola Dulgiarov post about metaborate substitution and finally I adapted the formula like bellow, after I substituted also the sodium ascorbate with ascorbic acid (highly available at low prices where I live)

Water ........................... 750ml
Sodium sulfite ........ 89.65 g
DTPA-Na5 dry .................. 1g || DTPA-Na5 40% sol .... 2.5 g
Borax ............................... 2.8 g
Sodium Hydroxide .. 1.59 g
Ascorbic acid .......... 10.67 g
Dimezone-S ................. 0.2 g
Water to 1L

Something else from my notes from 10 years ago:

1 gram of ascorbic acid can be neutralized by 0.477 g of sodium bicarbonate. Add these two to the beaker first, wait for the bubbling to nearly stop, and then add the other chemicals.​

​

Elsewhere in my notes:

12 g sodium isoascorbate = 10.7g ascorbic acid + 2.4g sodium hydroxide​

2.4 differs from your 1.59 g, so that calculation is worth rechecking.

I dislike sodium hydroxide because it's so hygroscopic that it gains weight while I'm weighing it! Furthermore, I don't know how much water has been absorbed into the powder in the bottle during storage. Thus, I cannot weigh it accurately. S. bicarb doesn't have this weight-gain problem.

Mark

 

[Alain Deloc]

Something else from my notes from 10 years ago:

1 gram of ascorbic acid can be neutralized by 0.477 g of sodium bicarbonate. Add these two to the beaker first, wait for the bubbling to nearly stop, and then add the other chemicals.​

​

Elsewhere in my notes:

12 g sodium isoascorbate = 10.7g ascorbic acid + 2.4g sodium hydroxide​

2.4 differs from your 1.59 g, so that calculation is worth rechecking.

I dislike sodium hydroxide because it's so hygroscopic that it gains weight while I'm weighing it! Furthermore, I don't know how much water has been absorbed into the powder in the bottle during storage. Thus, I cannot weigh it accurately. S. bicarb doesn't have this weight-gain problem.

Mark

Here is a link to a post of mine from this thread but few days ago that explains with a table how I did the calculations.
https://www.photrio.com/forum/threads/will-the-real-mytol-please-stand-up.84293/post-2765081
That 1.59g is the result of three weights of NaOH operation which are resulting from metaborate subtitution, isoascorbic substitution and metabisulfite substitution.

 

[bernard_L]

That's the point. None of the places, which have that stuff in stock, will show it in their price lists. It's an "if you ask us, we may find it in our inventory" type product. I could never figure out, what kind of illegal activity could possibly be pursued with DTPA and ATMP, none of the chemists could ever tell me, but for some reason this type of product is never ever listed officially. It's also on average easier to get the sodium salt instead of the free acid, since salts are less scary to chem dealers and shipping companies than acids.

The best starting point would be chem suppliers, who either have their own assortment of packaged photographic products, or who are known to supply the companies who do.

Acide diéthylène triamine penta acétique, 100 g, cas.number.title.metatag 67-43-6, commander en ligne⮞ carlroth.com

Acide diéthylène triamine penta acétique, 100 g, ≥99 %, pour la synthèse

www.carlroth.com

 

[Alain Deloc]

Acide diéthylène triamine penta acétique, 100 g, cas.number.title.metatag 67-43-6, commander en ligne⮞ carlroth.com

Acide diéthylène triamine penta acétique, 100 g, ≥99 %, pour la synthèse

www.carlroth.com

That's gold! But you need a company to make the purchase. On the checkout page there is a big warning at the bottom.
Attention : pas de vente aux personnes privées. / Attention : no sale to private persons.
But it's a starting point.

 

[bernard_L]

That's gold! But you need a company to make the purchase. On the checkout page there is a big warning at the bottom.
Attention : pas de vente aux personnes privées. / Attention : no sale to private persons.
But it's a starting point.

Sorry for the false hope. I had not tested it to checkout.
A fun fact is that DTPA is available as a fertilizer from various sources (aliexpress), but... pre-loaded with Iron.

Just a thought. Suvatlar

Rohchemie | Wolfgang Moersch Photochemie

www.moersch-photochemie.de

has lots of hard-to-source chemicals. Maybe if there is interest from DIY photographers he might buy 100g (250g?) of the stuff from Carlroth and part it out in 25g portions.

 

[Milpool]

I got my DTPA Na5 from Alphachem in Ontario but it was a few years ago so I don't know if they still have regular stock:

 

[bernard_L]

I got my DTPA Na5 from Alphachem in Ontario

Plus, due to shipping (+customs, VAT, and handling charge extortion) USA and EU live almost in parallel universes as far as material goods are concerned.

 

[Andrew O'Neill]

Plus, due to shipping (+customs, VAT, and handling charge extortion) USA and EU live almost in parallel universes as far as material goods are concerned.

Ontario is a Canadian province, not USA

 

[Milpool]

Plus, due to shipping (+customs, VAT, and handling charge extortion) USA and EU live almost in parallel universes as far as material goods are concerned.

The easiest thing to do is simply avoid ascorbates when scratch-mixing developers so that exotic sequestering agents aren’t needed. It is important to keep in mind the sensitometric properties of XTOL relative to D-76 are virtually identical for all practical purposes and the net improvement over D-76 in terms of grain/speed/sharpness is tiny - essentially trivial. Therefore it is quite a bit cheaper and simpler to make D-76 at home for the same results.

 

[Andrew O'Neill]

The easiest thing to do is simply avoid ascorbates when scratch-mixing developers so that exotic sequestering agents aren’t needed. It is important to keep in mind the sensitometric properties of XTOL relative to D-76 are virtually identical for all practical purposes and the net improvement over D-76 in terms of grain/speed/sharpness is tiny - essentially trivial. Therefore it is quite a bit cheaper and simpler to make D-76 at home for the same results.

Good point, but the keeping qualities of XTol also make it more attractive than D-76, for me anyways.

 

[Milpool]

Ontario is a Canadian province, not USA

Although there is a city called Ontario in California…

 

[Andrew O'Neill]

Although there is a city called Ontario in California…

Yes, but the chemical company is in Ontario, Canada.

 

[Milpool]

Good point, but the keeping qualities of XTol also make it more attractive than D-76, for me anyways.

Fair point if you’ve found it keeps longer than D-76. The other nice thing about XTOL is that it serves as its own replenisher so that makes it convenient to use in a replenishment regime.

 

[Andrew O'Neill]

Fair point if you’ve found it keeps longer than D-76. The other nice thing about XTOL is that it serves as its own replenisher so that makes it convenient to use in a replenishment regime.

Yup. That's how I usually use XTol.

 

[Alain Deloc]

Fair point if you’ve found it keeps longer than D-76. The other nice thing about XTOL is that it serves as its own replenisher so that makes it convenient to use in a replenishment regime.

That's why I want to mix Xtol from powders: for replenishment, or 1+1 dilution. Developing Xtol 1+1 at the actual price of XT3 per 1L is quite pricey. Replenishing Adox XT-3 requires to get the 5L pack (I did that in the past), which creates 2 scenarios : either I shoot a lot of black and white film during 12 months and use all developer, or just shoot 20 rolls, use a third of the chemistry, and throw away the rest after 12 or 15 months. Mixing from raw powders seems the most practical way for one that has the necessary chemicals. It's very cost effective and the waste is minimal.

 

[Alain Deloc]

Therefore it is quite a bit cheaper and simpler to make D-76 at home for the same results.

.. or Microphen/ID68 with Dimezone. Basically, Xtol is a Microphen with Dimezone-S instead of phenidone and hydroquinone replaced by vitamin C. I like more the results of Microphen, but is not really replenishable as I would like. After a while (around 30 rolls), it starts to lose details in the shadows, even if the highlights are rendered properly. I believe it's due to bromide build-up.

 

[Alain Deloc]

I dissolved some Dimezone-S in propylen glycol last year and I made a 10% solution perfectly clear and yellow. I noticed today that are few flakes floating in the yellow solution. I doubled the amount of PG making it a 5% solution and also I heated the solution up to 80 Celsius and stirred it for few minutes. I still have some flakes visible. What could be the cause? Is it the entire solution compromised?