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Allophane Determination in Ando Soils By Cation‐Exchange Capacity Delta Value
Author(s) -
Aomine Shigenori,
Jackson M. L.
Publication year - 1959
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1959.03615995002300030017x
Subject(s) - allophane , halloysite , chemistry , volcanic ash , cation exchange capacity , soil water , boiling , mineralogy , clay minerals , nuclear chemistry , geology , volcano , soil science , geochemistry , organic chemistry
One sample of H 2 O 2 ‐treated, iron oxide‐extracted soil is treated with 2% Na 2 CO 3 solution for 60 minutes and another with NaOAc of pH 3.5 for 15 minutes, at boiling. Both samples are washed with neutral NaOAc and the cation‐exchange capacity is determined with Ca replaced with NaOAc. The difference obtained between the two samples is referred to as the “cation‐exchange capacity delta value,” and averaged 100 me. per 100 g. for allophane from Ando soils of Japan developed on rapidly weathered volcanic ash and in some allophanes of Ross and Kerr. For example, the allophane content of fine clay of an Ando soil containing predominantly halloysite determined by delta value was 23.8% compared to 21.4% by water contents of constituent minerals.