I work with sodium hydroxide very often and I fail to see what the problem is.
for those who don't mind, it's worth to at least pointing out the risks.
sensitive to iron impurities like CD3
It is pretty well established by now that DTPA works well with proprietary Xtol.Now the real question is : will DTPA (or DTPA-Na5 salt) manage to protect the Xtol-patent formula from sudden failure?
specially contact with the eyes could be really bad.
But also I don't know if CD3 is that crazy as sodium ascorbate.
It is pretty well established by now that DTPA works well with proprietary Xtol.
However, (1) The Film Developing Cookbook 2020 p 63 notes potential problems come down to impurities in water and source chemicals.
The difference between proprietary Xtol and that made up from the patent is probably insignificant, certainly in terms of the DTPA:ascorbate ratio.
So it is to be expected that DTPA will almost always protect the Xtol patent formula as well, subject still to (1).
he s. metaborate sold by Photographer's Formulary is 8 mol. I checked the molecular weight (137.86) and CAS# (10555-76-7) in their SDS.
The XTOL patent specifies the pentasodium salt of DTPA, and not the free form. I apologize for that omission in the OP.
https://www.photrio.com/forum/threads/kodak-sodium-metaborate.186175/post-2456701
Mark
So it is to be expected that DTPA will almost always protect the Xtol patent formula as well, subject still to (1).
I think you calculated the substitution of metaborate by borax and the substitution of sodium ascorbate by ascorbic acid correctly. But the DTPA. 5Na needs to be recalculated and this will affect NaOH as well.
Example 1 calls for 1g of DTPA.5Na.
I think you calculated the substitution of metaborate by borax and the substitution of sodium ascorbate by ascorbic acid correctly. But the DTPA. 5Na needs to be recalculated and this will affect NaOH as well.
Sodium sulfite | 85 g | |
|
Sodium sulfite | (85+4.65) g | 89.65 g |
DTPA -Na5 | 1 g | |
|
DTPA -Na5 | 1 g | 1 g |
Sodium metaborate (8 mol) | 4 g | <==> | Borax 2.8 g + 0.6 gr NaOH | Borax | 2.8 g | 2.8 g |
Sodium isoascorbate | 12 g | <==> | 10.668 gr ascorbic acid + 2.42 gr NaOH | |
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|
Sodium Hydroxide | (0.6+2.42-1.43) g | 1.59 g |
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Ascorbic acid | 10.668 g | 10.67 g |
Dimezone S | 0.2 g | |
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Dimezone S | 0.2 g | 0.2 g |
Sodium metabisulfite | 3.5 g | <==> | 3.5gr sodium metabisulfite = 4.65gr sodium sulfite - 1.43gr NaOH | |
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My calculations agree with those in the box except for insignificant variations in the second decimal place.
Here is the old German data sheet that also has times for Xtol 1+2 and 1+3:
Hope to hear the result of your developing a film.
Sorry for ignorance BUT What IS 'DTPA' ?
I get this, assuming high purity of the ingredients:
Sodium metabisulfite + 2x Sodium hydroxide <-> ........ 2x Sodium Sulfite................. + Water
Na2S2O5.........................................2x NaOH...................................................2x Na2SO3.....................H2O
190.1..............................................2x40 =80.....................................2x 126.04 = 252.1........................18
67.62..........................................................28.44............................................................89.65
Another dangerous reaction where you need all the gear.
Oh, what should I expect to happen? Is it going to boil or something?Another dangerous reaction where you need all the gear.
Diethylene Triamine Penta Acetic acid (DTPA) is a metal complexing (chelating) compound part of the Aminocarboxylic acid (ethylenediamine-based) group. Other members of this group are Ethylene Diamine Tetra Acetic acid (EDTA) and Hydroxy Ethylene Diamine Tetra Acetic acid (HEDTA).
Diethylene Triamine Penta Acetic Pentasodium Salt (DTPA-Na5) is a salt of the above described acid and it is widely used to dissolve metallic impurities.
Diethylene Triamine Penta Acetic acid (DTPA) is a metal complexing (chelating) compound part of the Aminocarboxylic acid (ethylenediamine-based) group. Other members of this group are Ethylene Diamine Tetra Acetic acid (EDTA) and Hydroxy Ethylene Diamine Tetra Acetic acid (HEDTA).
Diethylene Triamine Penta Acetic Pentasodium Salt (DTPA-Na5) is a salt of the above described acid and it is widely used to dissolve metallic impurities.
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