© 2001, Silver Colloids. All rights reserved.
Determining The Properties of Colloidal Silver
By Francis S. Key and George Maass, PhD
The properties of substances are their characteristic qualities, many of which can be measured precisely and
expressed in numbers. Accurately quantifying such properties requires:
1. A scientifically valid theoretical approach.
2. Consistent process implementation.
3. Calibration values that can be traced to recognized standards.
This document will specifically address the properties of colloidal silver solutions that define the overall quality
of the solution. The operative definition of a colloid is a solution containing suspended particles whose sizes
range from 1 micron down to 0.001 microns (1 nanometer). The particles are suspended in pure water.
This document is intended for those seeking a scientific description of how to measure the relevant properties
that define the quality of a colloidal silver solution. This may include labs that are asked to perform quantitative
measurements of silver colloids, producers of colloidal silver solutions, producers of machines that make
colloidal silver as well as interested consumers who are technically inclined. Recently, much has been written
about colloidal silver that lacks scientific validity. This document will discuss the measurement procedures in
scientific terms such that an independent lab can duplicate the results described herein.
THE PROPERTIES OF INTEREST
1. Silver Concentration – total silver
a. Colloidal particles in ppm, percent of total.
Ionic silver in ppm, percent of total.
2. Electrical conductivity
3. pH of solution
4. Tyndall Effect – light reflected by a colloid
5. Zeta potential
6. Particle size distribution
Silver concentration is most frequently reported as total silver measured in milligrams per liter (mg/L), which is
numerically the same as parts-per-million (ppm). The total silver consists of silver in tw