Contamination To all,
I have been talking about contamination problems for a long time. Few people understand how serious the problem can be. There are many ways the brew can be contaminated, and it is often difficult to detect. I will briefly summarize some of the methods of detecting contamination. There is a huge amount of documentation that goes along with this. I will have to research the archives to find my old experiments that show this, which will take a while. In the meantime, here are the topics that need to be addressed and documented for a more complete understanding of the problem: 1. Taste 2. Purple Cs 3. Amber Color 4. Conductance Plot 5. Faraday Calculation 6. Tyndall 7. Flashlight Reflection 8. Conductance Drop 1. Taste Properly made cs has no taste. Some people have remarked of a metallic taste to their cs. This is due to contamination. It can be a serious problem if you are trying to introduce cs to someone new. As soon as they detect the metallic taste, they will never try cs again. When you remove the contamination, the taste disappears. 2. Purple CS If you mix saliva with cs, it will often turn purple, especially if you sit it close to a fluorescent light. If you put cs in your cat's dish, it can turn purple. This is due to contamination, probably sulfur. If you remove the contamination, the cs will not turn purple. Here's proof. The photo below compares cs after being held in the mouth for 12 minutes against raw cs. The sublingual cs is on the left. It shows the color of the dispersion from silver chloride has deepened from contact with saliva. I had carefully removed any contamination from the system before making the brew. http://silvercentral.org/misc/3f0d0d40.jpg Note the sample on the left does not show any trace of purple, even though I let it sit for several hours. To make certain, I let it sit for a week. There was no change. It did not turn purple. 3. Amber Color Sulfur contamination can cause the cs to turn various shades of color from light red to light amber. One of the shades is very close to the distinctive yellow color of silver hydroxide and it would be impossible for a newbie to tell the difference. Removing the sulfide will allow the cs to attain a colorless, clear solution if brewed properly. 4. Conductance Plot If you use a constant current source, the voltage across the cell decreases rapidly at the start of the brew, then changes very gradually near the end. http://silvercentral.org/zimag/cellvolt.gif This curve makes it very difficult to set a threshold voltage to terminate the brew at a known concentration. However, if you invert the equation and plot the conductance instead, you should get a straight line. Deviations from a straight line will tell you what is happening in the brew. Here's an example: http://silvercentral.org/zimag/conduct.gif The curve should immediately start increasing at the beginning of the brew. The curvature in Section #1 shows the effect of contamination, probably silver sulfide in this case. Here is what the curve should look like at the start of the brew. Notice the increase is in a straight line at the beginning. The gradual curvature is due to silver plateout at the cathode. This is normal for this particular setup. http://silvercentral.org/zimag/3f3a0491.gif 5. Faraday Calculation If you do a Faraday calculation and compare it to the conductance reading from a COM-100, the COM-100 should be a bit lower than the Faraday. This is due to silver plateout at the cathode, and perhaps a bit of silver hydroxide production at the anode. If the COM-100 reading is higher than the Faraday calculation, it is a clear sign of contamination. I'll post two different methods of making the calculation. You also need a good constant current supply to make the brew. I'll post a simple inexpensive design that gives precision temperature-compensated control down to the microampere level. 6. Tyndall Any Tyndall response is a sign of a bad brew. If the Tyndall occurs right at the end of the brew, it is due to silver hydroxide production in the Nernst Diffusion layer next to the surface of the electrode. If the Tyndall occurs at or near the start of the brew, it is most likely due to contamination. 7. Flashlight Reflection I don't know what to call this properly at the moment. A cheap white led flashlight you can get at a dollar store has a lot of emission in the blue part of the spectrum or above. If you turn the lights out and shine the flashlight at the brew, it should not show any reflection. If it does, it is a clear sign of contamination as shown below. http://silvercentral.org/zmake/dsc09906.jpg 8. Conductance Drop If the COM-100 reading drops significantly after the brew is placed in storage, it is a clear sign of contamination. I have measured as much as 60% drop. Ken recently posted measurements of a 65% drop. This is not due to silver and hydroxide ions combining in the solution. They only combine in the Nernst Diffusion layer during the brew. After the brew, the layer disappears, and the high ion concentration needed for the ions to find each other and combine no longer exists. To show this, I evaporated a 20uS brew so the volume dropped to 1/8 of the original volume. This increased the ion concentration by a factor of 8, from 20uS to 160uS. The solution remained clear, and showed not sign of Tyndall or yellow tint that would occur if the ions combined to form silver hydroxide. The experiment is documented here. Note I made an error in the calculation and came up with 80uS instead of the proper figure of 160uS. I also referred to the combination as "silver oxide". This is incorrect. You cannot make silver oxide in electrolysis with dw and silver electrodes. http://www.mail-archive.com/[email protected]/msg64061.html If you remove the contamination, you should get much less drop. I had been getting about 8% drop until recently, when all my silver somehow got contaminated. I have received a shipment of new silver and am preparing to restart the Colloidal Silver Development System, or CSDS. My eternal thanks to Renee for suggesting this marvelous idea. It is the most powerful and valuable method of analyzing the colloidal silver process I have ever seen. Thanks, Mike Monett -- 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]>
