The method proposed by Lamar et al in May 2014 recently became the international standard for the analysis of humic acids and hydrophobic fulvic acids in commercial humic products on July, 17, 2018.
Link:
www.humictrade.org/news-and-events/
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The Lamar method for fulvic acid is better than V&B, but is still inherently flawed. The minerals, fulvic and fulvates can add up to more than a million parts per million. It includes humic portions just slightly larger than fulvic acid. The same test material can vary by 15% fulvic content meaning there is no real standardization with fulvic acid.