n Vergelyking van verskillende metodes vir die ekstraksie en bepaling van aluminium in grond

Comparison of various methods for the extraction and determination of aluminium in soil. Four methods for the extraction and determination of AI in acid soils were compared using soil samples from a variety of sources and ranging in pH (KCI) from 3,3 - 4,4. The object was to select a quick, simple,...

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Published in: South African journal of plant and soil Vol. 6; no. 2; pp. 137 - 141
Main Author: Pretorius, Mardel and Beukes, D.J
Format: Journal Article
Language: Afrikaans
Published: Taylor & Francis 05-01-1988
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Summary: Comparison of various methods for the extraction and determination of aluminium in soil. Four methods for the extraction and determination of AI in acid soils were compared using soil samples from a variety of sources and ranging in pH (KCI) from 3,3 - 4,4. The object was to select a quick, simple, but reliable method for the determination of AI on a routine basis. Firstly, extractable AI was determined after a series of 22 extractions with O,2M NH4CI (22-extraction method). Although sound, this method is too laborious for routine use. The second method used 1M KCI as extractant and AI was determined spectrophotometrically after colouring with chrome azurol S (CAS method). This method resulted in much lower AI values than did the 22-extraction method. The third method involved extraction with 1 M KCI followed by a final titration with 0,025M HCI after complexing AI with KF. Aluminium values similar to those of the 22-extraction method were obtained and repeatability was superior to that of the CAS method. The fourth method, involving a single extraction of AI with 0,2M NH4CI, yielded the lowest values of AI of all methods compared. It appears that the titration method, because of its simplicity, excellent repeatability and ability to provide additional information on soil acidity, is potentially the most suitable method for the routine determination of AI in soils.
ISSN: 0257-1862
2167-034X