Paving the way for pyroligneous acid standardization: Rapid decoding and absolute quantification of active...

Pyroligneous acid (PA), a by-product of biomass carbonization with a history of over 500 years of use, remains limited to private applications despite extensive research. The absence of a simple and practical method for quantifying its active ingredients has hindered industrial standardization and legal commercialization. This study introduces a novel, rapid, and low-cost assay to determine the absolute content of organic acids (as acetic acid) and phenols (as guaiacol) in PA. By neutralizing diluted PA samples with NaOH and establishing linear regression models at pH 7.25 and 11.15, the absolute contents of these key components are calculated without specialized training. A simplified version directly converts NaOH consumption at these pH thresholds into concentration percentages. If further compositional detail is required, GC-MS relative data can be integrated using weighted average molecular weights for full absolute quantification. This method overcomes the commercial limitations of relative content measurements and provides a scientific foundation for PA standardization, certification, and market adoption. We encourage international validation to help establish universal technical standards, advancing not only PA utilization but also supporting sustainable development of the biochar industry. The approach may also extend to other natural extracts containing multi-component acidic and phenolic mixtures.