Journal article

Publication year: 2008

Pages: 786-790

Journal: Soil Science Society of America Journal

Volume number: 72

Issue number: 3

ISSN: 0361-5995

DOI Link: https://doi.org/10.2136/sssaj2007.0178N

Publisher: Wiley

Abstract: 
It is unclear whether persulfate digestions completely liberate P associated with mineral colloids in soil solutions and aqueous soil extracts. We tested a modified persulfate digestion using aqueous sod extracts and suspensions of goethite, gibbsite, illite, and montmorillonite that were exposed to 24 mu mol P L-1 as orthophosphate (ortho-P) or myo-inositol hexaphosphate (IHP). Digestion was performed by autoclaving (121 degrees C, 60 min) 5 mL of extract or suspension after the addition of I mL of solution, which contained 150 mmol L-1 K2O8S2 and 180 mmol L-1 H2SO4. Subsequently, 0.7 mL, of 188 mmol L-1 ascorbic acid was added and the sample was heated in a water bath at 95 degrees C for 60 min. For the samples where P was sorbed onto goethite and gibbsite, recoveries of total P were 97.2 +/- 3.7% (ortho-P) and 102 +/- 3.7% (IHP). For the samples where P was sorbed onto clay minerals, average total P recoveries were 99.2 +/- 5.1% (ortho-P) and 106 +/- 3.0% (IHP). No differences between total P concentrations measured in persulfate-digested soil extracts or with an additional digestion with HF and HNO3 were detected.

Harvard Citation style: Pagel, H., Ilg, K., Siemens, J. and Kaupenjohann, M. (2008) Total phosphorus determination in colloid-containing soil solutions by enhanced persulfate digestion, Soil Science Society of America Journal, 72(3), pp. 786-790. https://doi.org/10.2136/sssaj2007.0178N

APA Citation style: Pagel, H., Ilg, K., Siemens, J., & Kaupenjohann, M. (2008). Total phosphorus determination in colloid-containing soil solutions by enhanced persulfate digestion. Soil Science Society of America Journal. 72(3), 786-790. https://doi.org/10.2136/sssaj2007.0178N