Developer from red grape juice

Discussion in 'B&W: Film, Paper, Chemistry' started by Alan Johnson, Dec 10, 2011.

  1. Alan Johnson

    Alan Johnson Subscriber

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    The phenolic groups in red grape juice are mainly Anthocyanins, marked with 1 in the table:
    http://jn.nutrition.org/content/136/7/1766/T1.expansion.html
    Adding up,the total Anthocyanin concentration is 0.234 m-mol/L,for MW=450 this is 0.105g/L
    For comparison the concentration of pyrogallol in 1:100 PMK Pyro is 0.5g/L
    The Anthocyanins are subject to hydrolysis at high pH:
    http://www.demochem.de/p26_anth-e.htm

    GJ-1
    Red Grape Juice pH 3.7....................600ml
    Sodium Hydroxide...............................3g
    Phenidone.........................................0.2g
    pH =10.9

    HP5 at EI=200 was developed in GJ-1 60min 20C, ag 10s every 2min.
    The negatives were underdeveloped but printable.
    One negative was bleached in 100g/L ferricyanide+bromide and fixed.
    A very faint relief image caused by the tanning of the gelatin by Anthocyanin or derivatives is shown in the attachment.(It is possible to provide a much better image from unbleached negative).
    Anthocyanins are present at low concentration and may be hydrolysed but produce detectable tanning.
    Other red/purple berries contain Anthocyanins, as a curiosity it may be possible to make staining developers from them.
    Thanks for comment.
     

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  2. albada

    albada Member

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    I enjoy reading about your experiments in fundamental research. Thanks for doing this. Last month was cabbage, wasn't it? Or was it Quercetin?
    Anyway, you spent an hour agitating that tank every other minute, having no idea if you'd get anything.
    That's the patience a good researcher needs.

    Mark Overton