Effect of NaOH-EDTA extraction time on the degradation of phosphate compounds

Xiaoqian Jiang, Yuji Arai

Research output: Contribution to journalArticlepeer-review


A chemical extraction of soil organic- and poly‑phosphorus (P) with a 0.25 M NaOH +0.05 M ethylenediaminetetraacetic acid (EDTA) solution is the most widely accepted method for 31P NMR measurements. The chemical preservation is often questioned because of inconsistent extraction time (4–16 h) among researchers. In this study, the effect of extraction time on the degradation of common P compounds (phytic acid, pyrophosphate, 2-aminoethylphosphonic acid, adenosine 5′-triphosphate disodium, and tripolyphosphate) was investigated using a spectrophotometric method. No degradation was observed up to 16 h in most of the compounds except for tripolyphosphate. The hydrolytic degradation of tripolyphosphate was retarded initially due to a high ionic strength of the extractant but became apparent after 8 h.

Original languageEnglish (US)
Pages (from-to)77-79
Number of pages3
StatePublished - Aug 15 2018


  • EDTA
  • Hydrolytic degradation
  • NMR
  • P
  • Phosphorus

ASJC Scopus subject areas

  • Soil Science


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