The release last month from the International Org. for Standardization (ISO) has taken the accuracy of testing for the fulvic fraction of humic acids to a higher level and cast it into the world- wide arena by issuing #ISO 19822:2018(E) Test Method for determination of Humic Acids and Hydrophobic Fulvic Acids.
In 2014 the IHSS (Int’l Humic Substances Society) developed a new standardized method for determination of HA and FA contents in raw humate ores and in solid and liquid products produced from them.(1) Later that year the AOAC Int’l Journal published the method known as LAMAR, named after the leading scientist that developed the test, Richard Lamar.(1)
Up to that time, there existed several varying methods to quantify humic and fulvic acids. The most common tests being the V&B, LGB, CDFA, and Colorimetric methods. These tests are inaccurate as they are unable to identify a true fulvic acid percentage.
Four years later, August 2018, the Int’l Org for Standardization (ISO) issued their approval of what they stated as a “modified form of the “classical” technique described by Stevenson in the textbook: Humus Chemistry, 1994.(2) The method ISO outlines in their paper is, but for a few steps, identical to the LAMAR procedure, which scientists know, can affect results dramatically.
LAMAR & ISO Objectives and Differences
The LAMAR method established an accurate and reliable way to quantify humic acid (HA) and fulvic acid (FA) in raw ores and products. The insoluble material is removed from the alkaline dissolved HA and FA material.
The ISO method identifies hydrophobic fulvic acids (HFA) as separate from humic acids (HA) derived from the raw source material. The results determine the portion of fulvic acids that tend to repel or fail to mix with water and, furthermore, distinguishes HFA from mineral salts, polysaccharides, amino sugars, amino acids, proteins, acids, and carbohydrates.
I went through the two methods to determine any differences in protocol. The good news is that there are no major differences between the two methods; however, some of the steps do vary by time and temperature and may be critical differences (see table).
It appears that ISO took into account that some constituents found in humic substances, such as phenolic compounds, for example, are understood to be quite unstable when exposed to prolonged high temperatures or UV light. (3)(4)
Differences between the new ISO and LAMAR methods:
1. The first difference is the time of flocculation for the HA portion. LAMAR stirs for 6 hrs. while ISO stirs for 16-18 hrs. to ensure all of the HA is flocculated.
2. The second major difference is that after the HCl is added to flocculate the HA portion the LAMAR method lets the solution sit for 1-6 hrs., while the ISO method specifically lets the solution sit for 4 hrs. +/- 5 minutes in order to "minimize loss" of HFA.
3. Another difference is the temperature of drying the HA or HFA. LAMAR drys at 90°C (194°F) while the ISO method never exceeds 65°C (149°F) during any and all of the drying steps. The rationale is that the HFA is heat labile and may degrade at 90°C (194°F).
The Industry-Wide Problem for Human Health Supplementation
For decades, it has been difficult to accurately identify the fulvic acid portion of a humic substance without other constituents such as mineral salts, proteins, carbohydrates or mimickers of FA such as lignosulfonates. ISO agrees with the LAMAR definition that HFA are materials of low sulfur content containing no lignosulfates.
The popular test methods mentioned above produced wildly different FA readings, which lead to products being touted as 50% fulvic acid or even 100% fulvic acid. Until the LAMAR method was established as a standard test, the marketing of fulvic products led to misleading claims.
The new ISO Test is very close to the LAMAR Standardized Test Method. The longer time for flocculation could purify the FA to a greater degree. ISO’s test accounts for heat sensitivity of co-resident organic acids. The drawbacks of longer times applied in the ISO method lengthens the protocol significantly. It’s good news that the industry is embracing accurate standardized testing methods specifically for the fulvic acid fraction of humic acids.
1 Lamar et al.: Journal of AOAC International Vol. 97, No. 3, 2014