I decided to make this a separate post since it pertains to an unrelated matter:
SilverFox wrote:However, if you adjust the pH of the chlorite solution to slightly acidic, more of the chlorite will be able to pass through the stomach acid. In this case the sodium chlorite is transformed to chlorous acid. Chlorous acid seems to hold on to the chlorite in solution and prevent it from freely releasing chlorine dioxide when it contacts the stomach acid. In the duodenum the pH is adjusted to alkaline and the chlorite is ready to be absorbed into the body. Any chlorine dioxide produced in the stomach that makes it into the duodenum may also partially convert back to chlorite in the duodenum.
Many times on these forums, I have seen you discuss "activating" the sodium chlorite by lowering the pH of the solution to between 5 and 6. While chlorite does indeed need to be activated with an acid in order to form chlorine dioxide, in this case it seems that you have confused the concept of activation with that of
protection.
If acid is added to a chlorite solution to lower the pH, then a small fraction of the chlorite molecules will be converted to chlorous acid. This conversion takes place almost instantaneously upon mixing of the solution. Since chlorine dioxide is created by the reaction of chlorous acid molecules, this mildly acidified chlorite solution can be accurately referred to as being "activated" (at least with respect to Chlorine dioxide production).
Since the concept of activation is the opposite of that of protection, the chlorite solution could not be protected from further reaction with strong acids by the very species (chlorous acid) that makes the chlorite MORE reactive. In fact, I can state categorically that there is NO possible way that simply having small amounts of chlorous acid in solution with chlorite could protect either species from further reaction when mixed with a strong acid. The reason for this is that all H+ ions are equivalent to one another in every way, which means that the chlorite/chlorous acid molecules in the solution can't distinguish between H+ from the so-called "activation" step and H+ from the strong acid. Therefore, the reaction must ultimately proceed the exact same way as would an "unactivated" solution mixed with strong acid.
However, this does not completely rule out the possibility that lowering the pH of the chlorite solution could provide a protective effect against strong acids -- only that this protective action could not take place through the creation and action of chlorous acid. The key element here is the so-called "activation time" of 24 hours following the lowering of the solution's pH. During this time, it is possible that the acid may catalyze a reversible transformation of chlorite molecules into larger forms (such as dimers), driven by the fact that such dimers may be more stable in acid than the individual chlorite molecules. Thus, the dimers would remain stable in the presence of stomach acid, while in the duodenum they would convert back to individual chlorite molecules (which would be the more stable form in an alkaline environment).
An analogy for this might be the practice of searing meats before cooking them to form a protective layer around the meat to hold in the juices better. Still, in my opinion the above scenario would be a highly implausible route for stabilizing the chlorite. The other possibility is simply that the results of your experiments on this matter were corrupted in some way, but I would have to know more details about the procedures you followed to determine that. Alternatively, you may try lowering the pH of two chlorite solutions in an identical fashion, and then adding acid to one solution immediately and to the other after 24 hours to see if there is any additional "protection" of chlorite.
Mike
"If I have seen a little further it is by standing on the shoulders of Giants." - Isaac Newton