Keck, Hannes
- Department of Ecology, Swedish University of Agricultural Sciences
- University of Copenhagen
Research article2018Peer reviewed
Callesen, Ingeborg; Keck, Hannes; Andersen, Thorbjorn Joest
Methods for particle size distribution (PSD) determination by laser diffraction are not standardized and differ between disciplines and sectors. The effect of H2O2 pretreatment before a sonication treatment in laser diffraction analysis of soils and marine sediments was examined on soils with less than 1% C and some marine sediments.The method uncertainty for particle size analysis by the laser diffraction method using or not using H2O2 pretreatment followed by 2 min ultrasound and 1-mm sieving was determined for two soil samples and two aquatic sediments by analyzing ten replicates on a Malvern M2000 instrument. The carbon content was in the normal range for upland soils 0.1-0.9% C, but one of the aquatic sediment samples had a high carbon content (16.3% C) for which the H2O2 pretreatment was not feasible.The effect of H2O2 pretreatment on the PSD was small and not significant. The standard deviation (std) in particle size fractions increased with particle size. PSDs and std for some samples were presented for future reference. Similar to other studies, the content of clay and silt (by sieving/hydrometer, SHM) was lower by the laser diffraction method (LDM) than by the hydrometer method. To avoid confusion, LDM results for the < 2-mu m fraction should not be reported as a clay fraction to be used in texture classification. The absolute standard deviation of within-bin class was well below 1% in the colloidal fractions (using 2, 6, 8, and 20 mu m bin delimitations) and below 0.2-3% in the sand fractions.The LDM method requires new calibrated transfer functions for classification of soil textural class due to deviating results for colloidal fractions. It can be used without H2O2 pretreatment on soils containing less than about 1% C, but results should be corrected for 1-2-mm coarse sand content if higher than, e.g., 5%. If the analysis is not referring to a particular volume of sample, the correction for 1-2-mm material can be omitted.
Hydrometer and sieving; Laser diffraction; Malvern Mastersizer 2000; Method pretreatment; Soil texture; Texture classification
Journal of Soils and Sediments
2018, Volume: 18, number: 7, pages: 2500-2510
Environmental Sciences
Geosciences, Multidisciplinary
DOI: https://doi.org/10.1007/s11368-018-1965-8
https://res.slu.se/id/publ/94801