FULVIC ACID TESTING METHOD
- Ralf Ostertag, Chief Science Officer
FULVIC ACID QUANTIFICATION
Until recently, there has been no standardized analytical method that the scientific community could rely on for consistent accuracy to determine the quantity of fulvic acid in an extract. Without an industry standard, manufacturers and sellers of fulvic products used methods that resulted in various claims being made on labels, marketing literature and websites of commercial fulvic acid products. These claims have caused many scientists and consumers to question the validity and accuracy of these claims about fulvic acid content, which made the evaluation of fulvic products very difficult.
Analytical quantification methods in the past measured both humic and fulvic acid as ONE substance. This created analytical challenges and mass confusion for those products that are fulvic isolates, having no measurable or very low humic acid in them. It is also the primary reason that fulvic acid content claims were usually inaccurate and much higher than is being brought to light with the new standardized method.
THE LAMAR STANDARDIZED METHOD or
"A New Standardized Method for Quantification of Humic and Fulvic Acids in Humic Ores and Commercial Products"
Developed by a team of scientists and individuals from various organizations involved in soil science, the Lamar method was recently accepted as the standardized method for fulvic acid quantification by AAPFCO (Association of American Plant Food Control Officials), the HPTA (Humic Products Trade Association), and the IHSS (International Humic Substances Society) which consists of the world’s top humic/fulvic scientists.
PREVIOUS METHODS EXPLAINED
LGB - (aka modified Larry G, Butler method) - until the emergence
f the standardized Lamar method in 2015, this has been the most accurate of all testing methods for fulvic acid and may still hold promise since the results produced, with regards to fulvic acid content, are somewhat similar to the Lamar method.
Fulvic acid is condensed tannin and can be absorbed by a resin whereby it can be quantified much more accurately by reading the vanillin conjugates of the sample. The one disadvantage to this method, as compared to the Lamar method, is that it does not purify or separate the lignin sulfates from the fulvic acid fraction leading to some inaccuracies in the final FA result.
COLORIMETRIC - Humic acid is exposed to light; the amount of light absorbed is compared to the quantification value of a Sigma-Aldrich standardized sample taken from a mine in Germany. Although quick and easy, this method lumps the fulvic acid in with the humic acid producing poor quantification of fulvic isolates.
CDFA - (aka California method) This test was developed by the California State Department of Agriculture. This method does separate the humic and the fulvic but it then discards the fulvic solution and only measures the remaining liquid also including the organic ash content as part of the quantification result with no purification steps performed to remove the ash. This of course leads to various analytical inaccuracies. This is the only method that the California departments of agriculture will accept when registering a product. California does not recognize fulvic acid as separate substance from humic acid and requires that all label registrations list the content as humic acid only. Until 2017, Oregon also required using this method but has recently switched to the Lamar Method of fulvic acid quantification and now allows the label registration of fulvic acid as a substance apart from humic acid.
V&B - (aka Verploegh and Brandvold method) quantifies both humic and fulvic acid and is a quick, cost effective, and easy test to perform. It does not go through purification of the chemical reagents used to separate the humic and fulvic acids. This results in various inaccuracies that can produce inflated fulvic acid content readings since amino acids, lipids, carbohydrates and lignin sulfates are all lumped in with the quantification.