Pink Metol - Is This Normal?

Discussion in 'Black and White' started by vladsoare, Mar 5, 2009.

  1. Hi guys,
    I've been recently given 1kg of metol. It was in an old tin box which seemed to have never been opened. Upon inspection, I noticed that it doesn't look like the metol I had just bought a couple of weeks ago. That looked like white crystals, while this one is noticeably finer (like flour) and slightly pink.
    It looks as homogenous as it gets, I mean it's not like parts of it have become pink. It all looks the same. I know, because I transferred the entire contents of the box to another jar (I couldn't help it - I'm a fan of those brown glass jars and bottles). Nothing about its appearance would worry me if I didn't happen to have another batch of metol to compare it with.
    Is this pink shade normal? Or does it mean that it's dead?
    Thanks.
     
  2. White is the normal color. I have used some that was decades old and in a opened containner. It had a slight grey color to it but it worked fine. I have never seen a pink color. I suggest you just try it out and see how it goes. Powdered chemicals in sealed metal cans last just about forever so I would be surprised if it had any problems.
     
  3. It may mean that it has been exposed to water; maybe through humidity. I have only used Metol a couple of times, but I want to say that the solutions I used ended up in a pinkish hue as they were poured out of the tank. 1kg is a lot. I would hang onto that for practice rolls, if nothing else. It should go a long way if it is still good. Some of those Metol-HydroQ recipes use less than 10g of either.
     
  4. It occurred to me that, if the metol turns out to be unreliable, one way you might be able to still use it with less risk would be to mix it into homemade paper developers. That way, you'd only risk one piece of print paper at a time, instead of a whole roll of negatives.
     
  5. I've seen this. Somebody gave me an old bottle of metol and it was pinkish, giving a noticeably pinkish solution. I made up some D23 with it, and it was fine. Try 7.5 gm metol plus 100 gm sodium sulphite made up to 1 litre with water. Dilute 1+2 and try 8-10 minutes development time.
     
  6. Thanks guys.
    I'll try to mix some D-23 and see how it works.
     
  7. Update: I've mixed a liter of D-23. It has a pinkish gray tint, but seems to be working just fine. :)
    Thanks.
     
  8. Oxidized Metol is converted to the Metol sulfonate by sodium sulfite. This is a less active compound. Sodium ascorbate regenerates oxidized Metol, as does a combination of hydroquinone and sulfite. If you suspect the Metol is partly oxidized, you can use it in D-76, for example, by first dissolving the 2 g. of Metol in about 100 ml water, then dissolving the 5 g. of hydroquinone along with about 25 g. of the sulfite in a couple hundres ml water and adding it to the solution. At this point, the oxidized part of the Metol, if any, will have been regenerated. Finally, you can add the rest of the sulfite and the borax along with water to make a liter of D-76. You haven't put anything in that you would not ordinarilly put in D-76, but the order is different. Another approach would be to add a little sodium acorbate to the Metol-water solution before adding any sulfite. Yet a third approach is to use 8 grams of the ascorbate in place of the hydroquinone and mix it in water with the Metol before adding the usual amount of sulfite and the borax.
     
  9. Thanks, Patrick. That sounds interesting and easy to do. There are two things I'm not very sure about:
    First, how do I know if my batch of metol is really partly oxidized? I've mixed a liter of D-23 and developed a test sheet of Fomapan 100 for the time found on the Massive Development Chart. Although D-23 is said to be soft-working and non-highlight-blocking (at least that's what Ansel Adams used to say), I got an unexpectedly high contrast, with highlights looking as dense as they could get. In fact, it was the worst overdevelopment I had ever seen. That's why I assumed that the metol was fine, because I would expect oxidized metol to give lower, not higher contrast. But is this really a correct assumption? Is there any other way, I mean a chemical, not photographical, way of ascertaining that the metol is fine? Something like, I don't know, maybe mix it with something else, and see if anything in particular happens, either a change in color, or anything else?
    Second, if I apply your method above, how can I tell afterwards if it really worked or not? Will there be any visible difference? Like, let's say, if the original metol solution is pinkish, will the regenerated one become colorless? Or something like that?
    And while we're at it, is there a similar method for hydroquinone? I have a batch of pink hydroquinone that seems to be working fine. However, "seems to be working" is just a subjective assessment. Is there a better, less empirical, method of assessing a batch of hydroquinone and, if necessary, regenerating it?
    Thank you.
     
    eugen_mezei likes this.
  10. Vlad, your pink methol still works.
    Today I used it the first time, 10 and a half years after you sent it to me. Stood in the bottle you sent it at room temperature. Made Stöckler and developed a roll of Polypan-F exposed April 2012. It dries now, maybe tomorrow I scan, but it looks good so far.
     

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