Gravimetric Quantification of Hydrophobic Fulvic Acids in Lignite Material Using Acetone
Bibliographic record
Abstract
This study evaluated the gravimetric quantification of fulvic components in lignite material. The current standard method considered only components soluble in both alkali and acid solutions and adsorpted to a hydrophobic resin (DAX-8) at pH 1, identified as hydrophobic fulvic acids (HFA). HFA were desorpted using 0.1 M sodium hydroxide (NaOH) and run through a cation exchange resin (IR-120) to remove Na ions. HFA were quantified gravimetrically, including ash corrections. Steps involving IR-120, however, resulted in a large volume of analytical solution and a significant time of analysis, which became a disadvantage of this method. A modification to this method was proposed by replacing NaOH with acetone to desorpt HFA from DAX-8. IR-120 was not required, and a smaller volume of analytical solution was produced. Gravimetric, Fourier transform infrared (FTIR), and ionic analyses were completed in this study. Both standard and modified methods resulted in the presence of hydrophobic neutrals within the quantification of HFA. Acetone at 50% strength produced HFA results corresponding to those of NaOH. An adequate regeneration of DAX-8 was achieved using the modified method but not with the standard method. The modified method produced higher ash contents, but they did not affect its accuracy. This method significantly reduced the overall analytical time. This study showed the potential of acetone as a desorpting agent in the gravimetric quantification of HFA in lignite material.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".