Hello Marshall, They are actual measurements.
Here is a link to a label for a sodium chlorite/chlorine dioxide product. You should begin to get a feel for the difference between available and free chlorine dioxide in solutions. http://www.sanivex.com/pdf/EPA_Label.pdf There are a lot of variables involved with mixing, so we usually use theory to get into the ballpark, and then adjust according to actual measurements. I have found the Brix scale in a refractometer is an accurate way to determine the concentrations of citric acid and sodium chlorite solutions. A calibrated PH meter is used to monitor the activation process, and from that information tables can be produced to estimate the amount of free chlorine dioxide released during the activation. Unfortunately these tables are proprietarily so they are very difficult to find. Free chlorine dioxide is best determined with a colorimeter, but they do make test strips that give a very good approximation of what you have. I believe LaMotte makes them in the 0 - 10 PPM and 0 - 500 PPM ranges. Please note that these are different than chlorine test strips. Just to touch on the general rules... Sodium chlorite powder is only 80% pure. This means that you have to mix a 6.25% by weight solution to end up with a 5% sodium chlorite solution. Sodium chlorite solutions activated with acids only yield about 60% of the available chlorine dioxide. This means that a 5% sodium chlorite solution that should have 50000 PPM available chlorine dioxide actually only ends up having 30000 PPM available for use. In general, activation with 10% citric acid will result in about 10% of the available chlorine dioxide released as free chlorine dioxide. The proper activation ratio when using 10% citric acid is 1:1, and the optimum activation time is 10 minutes. In general, activation with 50% citric acid will result in about 20% of the available chlorine dioxide released as free chlorine dioxide. The proper activation ratio when using 50% citric acid is 1:5. That is 1 part 50% citric acid to 5 parts sodium chlorite. Once again the optimum activation time is 10 minutes. Activation with HCl is a little different. The concentration of HCl needs to be 1.2 times the concentration of the sodium chlorite you are going to activate. This means that if you have 5% sodium chlorite you would use 6% HCl. The activation ratio is 1:1, and the activation time is under 30 seconds. HCl drives the PH of the sodium chlorite low enough to release all of the available chlorine dioxide as free chlorine dioxide. Those are some of the basics. From there you can explore a number of possibilities and design a disinfecting system that fits your needs. Chlorine dioxide can be used to stabilize bacterial growth, or it can be used to kill off the bacteria. In water purification it is used as a biocide whereas in food processing it is used as a biostat. In general, chlorine dioxide technology deals in biocide applications and acidified sodium chlorite technology deals in biostat applications. Tom ----- Original Message ----- From: "Marshall Dudley" <[email protected]> To: <[email protected]> Sent: Saturday, March 27, 2010 7:25 PM Subject: Re: CS>Sodium Chlorite and Nail Fungus > Please advise. Are the numbers you give below actual measurements, or > computed theoretical numbers? Where did you get the information that > only about 10% will convert under those conditions? Can you refer me to > a paper, or url which discusses this? I was unaware of the incomplete > conversion with weak acids, and if correct, then you are correct that > the use of citric acid would be ineffective. If you actually measured > the chlorine dioxide content, can you tell me what instrument or > protocol you used? > > Marshall -- The Silver List is a moderated forum for discussing Colloidal Silver. Rules and Instructions: http://www.silverlist.org Unsubscribe: <mailto:[email protected]?subject=unsubscribe> Archives: http://www.mail-archive.com/[email protected]/maillist.html Off-Topic discussions: <mailto:[email protected]> List Owner: Mike Devour <mailto:[email protected]>
