- By Dr. Robert MacCuspie
- Jun 12, 2018
- Silver Science
Silver Myths Busted: Are TDS Meters Accurate for Measuring Colloidal Silver?
It’s human nature to be skeptical at times. We like to see data, find evidence, and hear stories to convince ourselves that certain things in life are true. So it’s certainly a fair question to ask if the amount of silver in a bottle really matches what is on the label.
Just like checking the air pressure in your tires. Sure, it looks like they have enough air in them, but checking with the appropriate tool is still necessary to be sure. So you reach for the right tool for the job, a tire pressure gauge, of course. Obviously, you wouldn’t check the air pressure in your tires using a bathroom scale. It’s the wrong tool for the job of measuring air pressure.
When it comes to measuring silver, tool selection is less obvious (unless of course you’re a trained chemist). When I previously worked at the National Institute of Standards and Technology as a Research Chemist, I loved talking to people about metrology, the science of measurements. So let’s unpack the science of picking the right tool to measure silver concentration.
How do you accurately measure silver concentration?
With analytical chemistry tools that are selective for silver metal. Examples include atomic absorption spectroscopy (AAS), optical emission spectroscopy (OES), and inductively coupled plasma mass spectroscopy (ICP-MS). NIC uses two AAS systems which were selected for the combination of accuracy and efficient operational use to evaluate the silver concentration ranges of our products.
Atomic Absorption Spectroscopy
A properly validated and calibrated AAS instrument will measure the concentration of metals, in this case, silver present in a liquid, and only the silver concentration. These scientific instruments cost tens of thousands of dollars and require specialized laboratories to operate safely. AAS instruments are not something you can buy on Amazon or run in your garage, and are only found in academic or corporate laboratories. To learn more about the specific models of AAS we own, check out Our Labs in The Learning Center.
Natural Immunogenics Corporation (NIC) uses AAS to measure the silver concentration 9 times for every batch they manufacture, following industry best practice Standard Operating Procedures, comparing National Institute of Standards and Technology (NIST)-traceable calibrations curves at the beginning and end of each measurement to ensure their accuracy and consistency, and only releases that batch if it falls within NIC’s rigorous specifications.
Using an AAS to measure silver concentration in a liquid is the equivalent of reaching for a tire pressure gauge to check your car’s tire pressures.
Total Dissolved Solids Meters (TDS) – What do they really measure?
According to the Water Research Center, “total dissolved solids test provides a qualitative measure of the amount of dissolved ions but does not tell us the nature or ion relationships.”
A total dissolved solids, or TDS, meter actually measures the conductivity of the water, then uses mathematical assumptions to estimate the amount of dissolved solids present.
What can contribute to the ppm reported by a TDS meter? Any salts or ions dissolved in water, which can include naturally occurring calcium and magnesium from hard water, sodium and potassium ions, lead and copper leached from pipes, chloride ions, and a whole host of other ionic compounds. Water’s conductivity increases as more ions are dissolved into the water. However, the conductivity increase varies depending upon the types of ions, leading to extreme inaccuracy in the measurement.
In other words, measuring water conductivity with a TDS meter to determine silver concentration is like using a Phillips screwdriver to tighten a flat head screw. It’s the wrong tool for the job.
Simply stated, TDS meters fail to measure silver concentrations in colloidal silvers in multiple ways, such as…
1. TDS measures conductivity, not silver concentration
2. TDS doesn’t measure solid metal particle concentrations
3. TDS doesn’t use correct mathematical assumptions to convert silver ion concentrations to an accurate ppm value
4. TDS meters measure all ions contributing to conductivity, and, therefore, are not selective to silver.
We’ve just unpacked a lot of science here, and it can certainly get confusing.
So how do you know who to trust when it comes to the measurement, safety*, purity, and effectiveness* of a silver product?
One way you can always trust a company’s measurements is to look for the NSF International mark that states products were manufactured in a certified GMP facility, just like Natural Immunogenics Corporation’s Sovereign Silver Bio-Active Silver Hydrosol™.
NSF International brings in subject matter experts to review the scientific validity and accuracy of all test methods used to support the release of our quality products. They audit the collected data, and ensure all staff are fully trained in the procedures they are performing. Our value of highest manufacturing and testing standards that are third-party verified offers you the confidence that our products are exactly what they are represented to be.
Another tool that may help you is our silver product comparison tool. You can compare Transmission Electron Microscopy (TEM) images of Sovereign Silver Bio-Active Silver Hydrosol ™ to other silver brands and products currently available in the marketplace.
If you have any additional questions about this information please contact us through this site or call our Customer Care team Monday – Fridays between the hours of 8:30 am and 5:30 pm EST.
Dr. MacCuspie holds a Ph.D. in Nanotechnology and Materials Chemistry and has over 17 years of experience in Nanotechnology, including nearly 10 years specifically in silver nanotechnology. He has worked for several US National Labs including the US FDA, Air Force Research Laboratory, and the National Institute of Standards and Technology (NIST), where he developed their silver nanoparticle reference materials and was an international leader in nanomaterial environmental health and safety (nanoEHS) research. He was the First Faculty and Director of Nanotechnology & Multifunctional Materials programs at Florida Polytechnic University, and served on their Board of Trustees. Dr. MacCuspie holds 1 US Patent , has written 2 book chapters and 42 peer-reviewed manuscripts which have been cited over 2,500 times with an h-index of 27.