In solution they are the same thing. I believe that you can use about the same mass of either compound. Jurgen On Thu, 26 Apr 2007 18:25:43 -0700 (PDT), Eric Nelson wrote > I have discovered that I am out of sodium bisulfite > and need to make some HCA tonight for prints I just > finished. > I have tons of sodium metabisulfite and have looked > through the archives to see if this compound is > specifically addressed as an AKA or substitute > compound for sodium bisulfite. > I've included some quotes below of Richard's that seem > to answer this question, so I'm wondering if there is > a definitive answer out there as to whether I can use > metabisulfite in place of bisulfite gram for gram in > the HCA formula or at what ratio it would need to be > at. > > I'm a cook not a chef so molar aspects of these > compounds and the Avogadro's number will go over my > head. ;-) > And what the heck is bisulfite lye? Found that > mentioned in one of my search results. > Eric > > "Long ago there was a discussion of what exactly was > meant > by sodium bisulfite in Kodak and other formulas. It > appears > that the compound is actually metabisulfite, or mostly > so. > Sodium metabisulfite is much less expensive than real > sodium > sulfite and is certainly suitable for this formula." > > ."various MSDS list either Sodium Bisulfite or > > Sodium Metabisulfite. > > > Kodak > > > Sodium Bisulfite appears to be mostly the > > metabisulfite. Evidently it > > > does > > > not matter which is used. > > > Because the formula is not published the amount of > > EDTA and Citrate are > > > not > > > firmly established. The MSDS for the concentrate > > (powder) lists the > > > amount > > > of either as 1 to 5% by weight. It disappears from > > the working solution. > > > It's possible the amount in the stock should be > > only 1 gram of each but I > > > think from Haist or somewhere I got the idea that > > it should be more. > > > Perhaps a compromise of 2 grams each should be > > used. > > > I think 15 grams of the bisulfite/metabisulfite is > > correct. In any case > > > the > > > target pH is 7.0" > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > ============================================================================================================= > To unsubscribe from this list, go to www.freelists.org and logon to > your account (the same e-mail address and password you set-up when > you subscribed,) and unsubscribe from there. -- WOW! Homepage (http://www.wowway.com) ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.