| Abstract: | Seven samples of commercial "humic acids", purchased from five different suppliers, were studied, and their characteristics were compared with humic and fulvic acids isolated from streams, soils, peat, leonardite, and a dopplerite sample. Cross-polarization and magic-angle spinning 13C NMR spectroscopy clearly shows pronounced differences between the commercial materials and all other samples. Elemental and infrared spectroscopic data do not show such clear-cut differences but can be used as supportive evidence, with the 13C NMR data, to substantiate the above distinctions. As a result of these differences and due to the general lack of information relating to the source, method of isolation, or other pretreatment of the commercial materials, these commercial products are not considered to be appropriate for use as analogues of true soil and water humic substances, in experiments designed to evaluate the nature and reactivity of humic substances in natural waters and soils. |
| Genre: | Article |
| ProdID: | 70015165 |
| Citation Author: | Malcolm, R. L.; MacCarthy, P. |
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| Citation End Page: | 911 |
| Citation Issue: | 9 |
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| Citation Language: | English |
| Citation Larger Work Title: | Environmental Science and Technology |
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| Citation Number Of Pages: | 8 |
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| Citation Search Results Text: | Limitations in the use of commercial humic acids in water and soil research; 1986; Article; Journal; Environmental Science and Technology; Malcolm, R. L.; MacCarthy, P. |
| Citation Start Page: | 904 |
| Citation Volume: | 20 |
| Citation Year: | 1986 |
| Type: | citation/reference |
| Text: | Limitations in the use of commercial humic acids in water and soil research; 1986; Article; Journal; Environmental Science and Technology; Malcolm, R. L.; MacCarthy, P. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 1 Jan 1986 00:00 -0600 |
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