The extraction and characterization of humic substances from Philippine sources. Part 1: Philippine soils.

Authors

  • Elma C. Llaguno Natural Sciences Research Institute and Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City
  • Victoria A. Vicente-Beckett Natural Sciences Research Institute and Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City
  • Glenda Soriano Natural Sciences Research Institute and Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City
  • Noel Miraflor Natural Sciences Research Institute and Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City
  • Erlinda T. Kua Natural Sciences Research Institute and Institute of Chemistry, College of Science, University of the Philippines, Diliman, Quezon City

DOI:

https://doi.org/10.26534/kimika.v8i1.17-39

Keywords:

humic substances, Philippine soils, ash content, ultra violet, infra red, elemental composition

Abstract

Humic substances (HS), the major natural sources of organic carbon in the environment, were isolated from several Philippine soils. The study sites included a peat deposit (at Tinambulan, Cotabato), agricultural farms (at San Pedro, Laguna and Kabacan, Cotabato), and a marshy site (Paombong, Bulacan).

The physicochemical characteristics of two major HS components, humic (HA) and fulvic (FA) acids, were determined. The ash content of the HA and FA isolates depended on the HS source and on the extent of hydrofluoric acid treatment. H/C and N/C atomic ratios of soil HA ranged between 0.89-1.29 and 0.045-0.068 nm, respectively. The common general feature of the uv-visible spectra of both isolates was a broad peak at 190-240 nm. Infrared spectra of peat and some Kabacan soil (non-irrigated/soybean-cultivated, and irrigated/corn-cultivated) HA extracts and of FA isolates from peat, Paombong, and Kabacan soil (non-irrigated both soybean- and corn-cultivated) exhibited IR absorption bands which were typical of HA or FA described in the literature. However, the isolates from San Pedro (non-irrigated/rice cultivated) and Kabacan (non-irrigated/corn-cultivated; irrigated/soybean-cultivated) soils showed IR absorption bands, indicative of proteins and carbohydrates.

Downloads

How to Cite

Llaguno, E. C., Vicente-Beckett, V. A., Soriano, G., Miraflor, N., & Kua, E. T. (1992). The extraction and characterization of humic substances from Philippine sources. Part 1: Philippine soils. KIMIKA, 8(1), 17–39. https://doi.org/10.26534/kimika.v8i1.17-39

Issue

Vol. 8 (1992)

Section

Research Articles

License

Authors who publish with this journal agree to the following terms:

  1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
  2. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
  3. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).