Improved version of DS-10 by Ryuji Suzuki?

[albada]

Reports say that DS-10, created by Ryuji Suzuki, is comparable to XTOL. A few years ago, Ryuji said that he had improved DS-10, and implied that he would publicize the formula (see http://www.apug.org/forums/archive/i...p/t-25194.html). Did he ever make that improved formula public? His web-site no longer has his formulas, which is a pity.

Here's the formula of DS-10 from digitaltruth.com. I don't know if this is the improved formula:

Water ......................... 750 ml
Dimezone S .................... 0.15 g
Ascorbic Acid ................. 8 g
Boric Acid .................... 4 g (Ryuji: Use 2g to match XTOL's dev-time and pH of 8.2. Called "DS-10X")
Salicylic Acid ................ 1 g
Sodium Sulfite (anhydrous) .... 75 g
Triethanolamine, 99% .......... 10 ml (TEA)
Water to make ................. 1 L

Thanks,

Mark Overton

[Gerald C Koch]

I am not aware of any published formula for an improved version of DS-10. RS sold his formulas to a company who was manufacturing them under their own name. IIRC, the improved version was said to use a chelating agent different from the salicylic acid/triethanolmine mixture.

[albada]

I am not aware of any published formula for an improved version of DS-10. RS sold his formulas to a company who was manufacturing them under their own name. IIRC, the improved version was said to use a chelating agent different from the salicylic acid/triethanolmine mixture.

I thought the salicylic acid was a chelating agent (for iron?), but I'm wondering why the TEA is in there, considering that there's plenty of alkali in the 75 g of sulfite. Is TEA also a chelating agent for something? Or could the TEA also perform a role in development?

I'm wondering if the salicylic and TEA can be dropped if distilled water is used.

Mark Overton

[brucemuir]

Would someone be so kind as to describe the action/function of a "chelating agent"?

Or perhaps direct me to somewhere I could read about this. I did look it up once and the wiki wasn't to informative or maybe I wasn't understanding.

I ususally see it in relation to color C41 process.

[Gerald C Koch]

I thought the salicylic acid was a chelating agent (for iron?), but I'm wondering why the TEA is in there, considering that there's plenty of alkali in the 75 g of sulfite. Is TEA also a chelating agent for something? Or could the TEA also perform a role in development?

I'm wondering if the salicylic and TEA can be dropped if distilled water is used.

Mark Overton

The TEA is also a chelating agent and with the salicylic acid seems to increase the chelation of iron.

Iron is a common impurity of many inorganic chemicals and so you cannot get around not using a chelating agent just by mixing the developer with distilled water. Salicylic acid can be obtained from many compounding pharmacies. It shouldn't be expensive. I purchased 250 g a few years ago for $1o. TEA can be purchased from such locations as www.chemistrystore.com.

[Photo Engineer]

TEA here functions as an alkali. TEA is so weak as a chelating agent, it is not considered one as such and is often used in combination with a "real" chelating agent such as EDTA. A chelating agent can be considered a material which combines with specific metal ions and reduces their activity or prevents side reactions from taking place. A good place to learn about TEA and chelating agents is via Wikipedia.

The Sulfite is primarily a silver halide solvent and acts in a fashion similar to its role in D-76.

PE

[Alan Johnson]

Here is the original formula from the former site:

DS-10
water......................................700ml
sodium sulfite,anhydrous.............75g
triethanolamine,99%...................10ml
ascorbic acid.............................8.0g
Dimezone S...............................0.15g
salicylic acid..............................1.0g
boric acid..................................4.0g
water to make............................1.0 liter
target pH...................................8.00 +/- 0.05

Digitaltruth differs only wrt an insignificant change in the initial amount of water used.

[albada]

TEA here functions as an alkali. TEA is so weak as a chelating agent, it is not considered one as such and is often used in combination with a "real" chelating agent such as EDTA. A chelating agent can be considered a material which combines with specific metal ions and reduces their activity or prevents side reactions from taking place. A good place to learn about TEA and chelating agents is via Wikipedia.
PE

Everyone, thanks for the interesting information.
So the TEA isn't primarily for chelation/sequestration, which makes me wonder why two alkalis are needed (TEA and sulfite).
Do you suppose the TEA is needed to convert the ascorbic acid into ascorbate?
If so, could sodium bicarbonate be used instead?
Hmm, come to think of it, I'm not even sure that the ascorbic acid needs to be converted to ascorbate to be super-additive with phenidone.

I know these additional chems are easy to buy, but I'm trying to avoid turning into a chemical-collector.

Thanks,

Mark Overton

[albada]

The TEA is also a chelating agent and with the salicylic acid seems to increase the chelation of iron.

As PE implied in his response, you're saying that TEA and salicylic acid have a super-additive-like effect in chelating iron?

I did a google search for sequestering iron, and it appears that there are few methods of dealing with it. EDTA (which I think is in XTOL) and sodium tripolyphosphate (STP, not TSP) are a couple of choices.

Mark Overton

[Photo Engineer]

The two bases may be to adjust to the proper pH, but I see that the formulas above differ in pH with no explanation. In any event, use of 2 bases is not that unusual. I don't rule out chelation from TEA, just not as its primary function doe to its weak power as a chelating agent compared to its strong power as a base.

Borate may offer some buffer capacity. Salicylic Acid is a weak chelating agent as well. It is claimed by some to offer protection to Ascorbates from oxidation by metal salts.

Salsylic