Journal
PLOS ONE
Volume 15, Issue 8, Pages -Publisher
PUBLIC LIBRARY SCIENCE
DOI: 10.1371/journal.pone.0238061
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [51978347]
- Shandong Province Agricultural Major Application Technology Innovation Project [20182130106]
- Shandong Province Key Research and Development Program [2018GSF117005]
Ask authors/readers for more resources
The method of non-aqueous conductivity titration (NACT) of organic weak acids was applied to quickly and accurately determine the phenolic-hydroxyl and carboxyl-groups contents in humic acid. By varying the pH of the humic-acid sample, the concentration of the titrant, and the nitrogen-gas flow rate, the optimal titration conditions were determined to be a sample pH of 4, titrant concentration of 0.05 mol/L, and nitrogen-gas flow rate of 80 mL/min. Applying the detection method to p-hydroxybenzoic acid showed that its phenolic-hydroxyl content was 758.82 +/- 111.76 cmol/kg and carboxyl content was 744.44 +/- 51.11 cmol/kg. The theoretical phenolic-hydroxyl and carboxyl-groups contents of the p-hydroxybenzoic acid were 723.96 cmol/kg respectively, indicating that the method can accurately quantify the carboxyl and phenolic-hydroxyl groups in the sample. The NACT was used to measure the phenolic-hydroxyl and carboxyl-groups contents in humic acid quickly and accurately. In addition, 29 humic acid samples from 8 provinces of China covering the main humic-acid producing areas were collected and analyzed for acidic-groups content using the reported method.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available