Humic Acid


In this section a question and answer summary is given about the structure of humic acid molecules. For a full explanation of these answers please refer to the section entitled “Structure and Origin of Humic Acids and their Relationship to Kerogen, Bitumen, Petroleum and Coal.”

Q Are there many humic acid molecules?
A Yes, probably thousands (complexity like components in petroleum).

Q When one sees complex published structures containing many aromatic groups and links, are they correct?
A No,- they do not resemble humic acid molecules.

Q What are the molecular weights of humic acids?
A In the vicinity of 800 – 1200 amu (unaggregated).

Q What structures do humic acid molecules contain?
A These structures:

Q Is the exact polymeric structure of any humic acid molecule known?
A No, but these can be postulated as major structures, either by themselves or with other groups listed above present in the chain:

A Are there minor polymeric components?
Q Yes, these have been found:

C17-C30 alkanes, considered to be degradation (probably decarboxylation) products

R[CH2CH2]n-H where R = C18H37O4

C20H40N305[(CH2)mO]n-H where m = 2 or 3 and n = 1-3

Q Are there minor non-polymeric components?
A Yes, such as succinic, maleic, oxalic and ketoglutaric acids. Minor amounts of aromatic acids such as vanillic and syringic acids in terrestrially-derived humic acids are considered to be contaminants.

Q Does the humic acid molecule change structure with the environment?
A Yes, there are two major structural changes. The gem-diol group present in the solid can lose a molecule of water on dissolution in certain solvents or at different concentrations in a given solvent. Also, the conjugate chelate group can change its equilibrium between an enol-keto and di-keto group, depending on the solvent and concentration. A minor keto-enol change may also occur.

Q What effect does the dynamic nature of the humic acid molecule as described above have on the properties of humic acids?
A A single molecule changes its structure and chemistry eternally, and is therefore very difficult to analyze, and gives the impression that humic acids are composed of an infinite variety of molecules.

Q Can the structure of underivatized humic acids be determined?
A Probably not, because of the dynamic nature of humic acid molecules described above.

Q What are the best humic acid derivatives?
A Butylated derivatives; butylated plus lactonized derivatives; reduction with Raney Nickel or lithium aluminium hydride followed by acetylation or derivatization with pentafluoropropionic anhydride.

Q What are the best techniques for investigating the structure of derivatized humic acids?
A Fluorescence and solution FTIR. HPLC-MS, FT-MS and NMR are also useful, but only for the most hydrophobic derivatives.



  1. HELLO
    Please say me how many humic and fulvic acid do have Carbon? can you send MSDS for of fulvic and Humic acid to my mail?
    your sincerely fakhri kalbasi

    Comment by fakhri — 2009 @ 2:54 pm

    • Dear Fakhri Kalbasi

      There are perhaps 30 carbons in fulvic and humic acids, but this is only a guess. I do not sell fulvic and humic acids, so I do not have an MSDS.



      Comment by humicacid — 2009 @ 6:48 pm

  2. I have a MSDS if you want to contact me.

    Comment by desmond smith — 2009 @ 7:44 pm

    • Hello Desmond

      Please send me your MSDS.



      Comment by humicacid — 2009 @ 11:43 am

    • Hello Desmond,
      Could you please send me MSDS.
      Thank you,

      Comment by Alex — 2009 @ 5:16 pm

  3. Dear Michael,
    Thank you for posting this information.
    Given your obvious expertise, I was curious if you had any thoughts about how much humic and fulvic is best supportive of human health.
    My products are very concentrated–min Fulvic at 10% or 100,000 ppm with serving suggestion of one full ounce for maintenance (more if needed). Our Humic 30%/Fulvic 70% blend contains Super Concentrated Fulvic so it still requires only one ounce for the same concentration so customers don’t have to buy 2 products which is more economical.
    In my market analysis and competitor product testing, most Humic and Fulvic supplements sold on the internet test between 1% (10,000 ppm) and 6% (60,000 ppm) Fulvic and many test much lower. Serving suggestions of these products make it even more confusing about what people are getting–for example one is very concentrated, but recommends only a few drops so the net Fulvic delivered is minuscule. Sad.
    The concentration in our products is the concentration I personally used to assist my recovery (I also used both Humic and Fulvic).
    The problem is that I am wondering if the concentration doesn’t need to be this high–I keep being told this. I am not into greed and I could lower prices even more if the concentration is lower to benefit more people, or keep it at this concentration, but lower the serving suggestion. I can’t seem to get good advice or any consensus.
    Thank you for any thoughts you may care to share.
    P.S. Imagine what could be accomplished if people in our industry (any industry) could cooperate and collaborate and try to put ego aside for the greater good.

    Comment by CareyLyn Carter — 2009 @ 4:13 am

    • Hello CareyLyn

      I have very little expertise in the use and/or benefits of humic and fulvic acids in human or animal health. What I know is that there is massive confusion about what humic and fulvic acids actually are, and on top of that there are many unsubstantiated claims for the commercial products. This is surprising because Russian researchers in the 1930s did a lot of research about the benefits of humic acids for human health, but not much valid, rigorous research has been done since. I cannot recommend that these findings from the 1930s be accepted though, because the research back then was very crude.



      Comment by humicacid — 2009 @ 6:25 pm

  4. any characterisation that can determine if the black compound in my reaction is humic acid, fulvic acid or humin? thanks !

    Comment by angel — 2009 @ 6:46 pm

    • Hello Angel

      Humin is insoluble in alkali such as sodium hydroxide, so any insoluble matter could be humin. Humic and fulvic acids can be differentiated by their visible (or better, fluorescence) spectra. Both have a maximum in the region of 420-450 nm (fulvic closer to 420 nm and humic closer to 450 nm), but the fulvic acid spectrum falls more rapidly than the humic acid spectrum. Humic acid will still have a considerable absorption at 600 nm compared to 450 nm, whereas fulvic acid will have a relatively lower absorption at 600 nm compared to 420 nm.



      Comment by humicacid — 2009 @ 12:14 pm

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