Abstract
Some batches of phosphoric acid contain impurities that affect calorimetric determination of urea in soil extracts by the method of Douglas and Bremner, which involves measurement of the red color formed when an aliquot of extract is heated with diacetyl monoxime and thiosemicarbazide in the presence of phosphoric and sulfuric acid. A modification of this colorimetric procedure is described that permits use of phosphoric acid containing these impurities and allows accurate and precise determination of urea in soil extracts.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1163-1170 |
| Number of pages | 8 |
| Journal | Communications in Soil Science and Plant Analysis |
| Volume | 10 |
| Issue number | 8 |
| DOIs | |
| State | Published - Jan 1 1979 |
| Externally published | Yes |
Keywords
- diacetyl monoxime
- soil extracts
- urea
ASJC Scopus subject areas
- Agronomy and Crop Science
- Soil Science