Quadrafos

[renevich]

I'm looking for a substitute for Quadrafos CAS 14986-84-6 since this chemical seems almost imposible to source out. Any wisdom sharing on this will be very much appreciated

 

[Anon Ymous]

Well, it's a chelating agent and for the most part can be substituted by something that does the same thing. Sodium hexametaphosphate for example is such an agent and easily obtainable. The fine detail though is that some of these agents can affect the pH of the solution where they're used. In such cases, knowing the target pH is required and has to be corrected with a base or acid. Where exactly do you want to use it?

 

[renevich]

Thanks for your quick response and informative reply. I intend to use it in an alternative FD for E6 that Grant Haist mentions in his book MODERN PHOTOGRAPHIC PROCESSING (Vol 2 pg 537). The target PH he mentions is 9,25.

 

[Anon Ymous]

Sodium hexametaphosphate is a substitute and since you know the target pH things are relatively simple. Are you sure about the pH value though? 9,25 sounds a tad too low. Perhaps you meant 9,65?

 

[renevich]

9.25 @ 27 C is what is called for.

 

[renevich]

Sodium hexametaphosphate is a substitute and since you know the target pH things are relatively simple. Are you sure about the pH value though? 9,25 sounds a tad too low. Perhaps you meant 9,65?

WOuld you say that the substitution would be weight by weight? Or should I consider a factor in the substitution?

 

[Anon Ymous]

WOuld you say that the substitution would be weight by weight? Or should I consider a factor in the substitution?

Typical amounts used are 2 to 5g/l, with 2g/l being a usual starting point. Keep in mind that these chelating/sequestering agents are optional if you use distilled - deionised water. It wouldn't hurt to include some though. Modern commercial formulations are likely to use ATMP and/or DTPA salts.

BTW, what developing agents does this formula use? Phenidone (or a derivative like Dimezone S) and Potassium Hydroquinone Monosulfonate?

 

[Photo Engineer]

A reminder! Grant's book was completed a few years before the E6 formulas were finalized and released. Therefore, I would be cautious about anything that early.

In fact, it is a very early formula from the Color Division of the Research Labs.

PE

 

[renevich]

Typical amounts used are 2 to 5g/l, with 2g/l being a usual starting point. Keep in mind that these chelating/sequestering agents are optional if you use distilled - deionised water. It wouldn't hurt to include some though. Modern commercial formulations are likely to use ATMP and/or DTPA salts.

BTW, what developing agents does this formula use? Phenidone (or a derivative like Dimezone S) and Potassium Hydroquinone Monosulfonate?

Well the formula calls for 2 gr of quadrafos so I guess you're implying that I should substitute it with 2 gr of sodium hexametaphosphate, correct? The formula does use phenidone (1-Phenyl-3-pyrazolidone) and hydroquinone.

 

[renevich]

A reminder! Grant's book was completed a few years before the E6 formulas were finalized and released. Therefore, I would be cautious about anything that early.

In fact, it is a very early formula from the Color Division of the Research Labs.

PE

Thanks Mr. Mowrey. What would you suggest instead as a FD, and here I quote Grant Haist's introduction to the formula I'm interested in, for being "claimed to provide substantially the same color image from fresh or aged color materials"? I'm aiming at getting better results from very expired ektachrome.

 

[Photo Engineer]

I suggest using the real chemistry from a dealer rather than mixing your own. Among other things, the final formula used Hydroquinone Mono Sulfonate Potassium salt. This gives over all, better image quality wrt color, grain and sharpness.

PE

 

[renevich]

I suggest using the real chemistry from a dealer rather than mixing your own. Among other things, the final formula used Hydroquinone Mono Sulfonate Potassium salt. This gives over all, better image quality wrt color, grain and sharpness.

PE

Thank you. I do use the real chemistry from tetenal and the results are dissapointing with very expired ektachrome. No surprise indeed, since it is very expired. Just want to give it a try. I'll look up the Hydroquinone Mono Sulfonate Potassium salt for starters. I guess Antec chemicals would be the possible source, correct?

 

[Anon Ymous]

Since you are using using expired film, you may be able to correct colour shifts to some extent by modifying the colour developer's pH. Tetenal's instructions mention what changes must be made to compensate for colour shifts, but you may be able to adjust FD too. Additional potassium iodide in the FD can reduce blue shifts, especially at the higher densities.

Of course, all these may prove to be futile and you might actually waste time and chemicals...

 

[renevich]

I do use current and less expired film too, but your suggestion may lead me to optional alternative separate batches for expired emulsions. In any case it is indeed another route to explore. Thanks again.

 

[Photo Engineer]

Thank you. I do use the real chemistry from tetenal and the results are dissapointing with very expired ektachrome. No surprise indeed, since it is very expired. Just want to give it a try. I'll look up the Hydroquinone Mono Sulfonate Potassium salt for starters. I guess Antec chemicals would be the possible source, correct?

Antec might be a source as well as the Photographer's Formulary.

PE

 

[Rudeofus]

Here is a good set of formulas for E6 FD and E6 CD. Both formulas use Sodium Hexametaphosphate as water hardness sequestrant.