Phosphate elution from anion-exchange membranes in soil analysis

Suwei Xu; Andrew J. Margenot

doi:10.1002/ael2.70012

Phosphate elution from anion-exchange membranes in soil analysis

Research output: Contribution to journal › Article › peer-review

Abstract

Resin-extractable phosphate (PO₄-P) is a widespread sink-based measure of soil bioavailable phosphorus (P) used in biogeochemistry and soil fertility. However, acid elution of P may hydrolyze organic P and thus compromise measurement of PO₄-P. We evaluated sodium bicarbonate (NaHCO₃) as an alternative to sulfuric acid (H₂SO₄) for PO₄-P elution. We found 0.5 M NaHCO₃ achieved ≈100% PO₄-P recovery at higher initial PO₄-P concentrations (20 and 30 mg P/L), compared to 95%–98% with 0.25 M H₂SO₄. For 24 soil samples representing all 12 USDA soil orders, NaHCO₃ elution yielded 9.6% higher resin extractable PO₄-P than H₂SO₄. Additionally, the PO₄-P remaining in water extract after resin removal (H₂O_re-PO₄) was consistently quantifiable, and constituted up to 46% of total extractable PO₄-P. These results demonstrate (i) NaHCO₃ is a more effective eluent for resin extractable P than H₂SO₄, and (ii) H₂O_re-PO₄ should be quantified when measuring resin extractable P.

Original language	English (US)
Article number	e70012
Journal	Agricultural and Environmental Letters
Volume	10
Issue number	1
DOIs	https://doi.org/10.1002/ael2.70012
State	Published - Jun 2025

ASJC Scopus subject areas

Agronomy and Crop Science
Soil Science
Management, Monitoring, Policy and Law

Online availability

10.1002/ael2.70012

Library availability

Discover UIUC Full Text

Cite this

@article{1463420c38444e68865fcc29288b037e,

title = "Phosphate elution from anion-exchange membranes in soil analysis",

abstract = "Resin-extractable phosphate (PO4-P) is a widespread sink-based measure of soil bioavailable phosphorus (P) used in biogeochemistry and soil fertility. However, acid elution of P may hydrolyze organic P and thus compromise measurement of PO4-P. We evaluated sodium bicarbonate (NaHCO3) as an alternative to sulfuric acid (H2SO4) for PO4-P elution. We found 0.5 M NaHCO3 achieved ≈100% PO4-P recovery at higher initial PO4-P concentrations (20 and 30 mg P/L), compared to 95%–98% with 0.25 M H2SO4. For 24 soil samples representing all 12 USDA soil orders, NaHCO3 elution yielded 9.6% higher resin extractable PO4-P than H2SO4. Additionally, the PO4-P remaining in water extract after resin removal (H2Ore-PO4) was consistently quantifiable, and constituted up to 46% of total extractable PO4-P. These results demonstrate (i) NaHCO3 is a more effective eluent for resin extractable P than H2SO4, and (ii) H2Ore-PO4 should be quantified when measuring resin extractable P.",

author = "Suwei Xu and Margenot, {Andrew J.}",

note = "This work was supported in part by Illinois Nutrient Research and Education Council award #2021\u20104\u2010360731\u2010469 (Andrew J. Margenot) and by National Science Foundation award #2125626 (Andrew J. Margenot).",

year = "2025",

month = jun,

doi = "10.1002/ael2.70012",

language = "English (US)",

volume = "10",

journal = "Agricultural and Environmental Letters",

issn = "2471-9625",

publisher = "John Wiley & Sons, Ltd.",

number = "1",

}

TY - JOUR

T1 - Phosphate elution from anion-exchange membranes in soil analysis

AU - Xu, Suwei

AU - Margenot, Andrew J.

N1 - This work was supported in part by Illinois Nutrient Research and Education Council award #2021\u20104\u2010360731\u2010469 (Andrew J. Margenot) and by National Science Foundation award #2125626 (Andrew J. Margenot).

PY - 2025/6

Y1 - 2025/6

N2 - Resin-extractable phosphate (PO4-P) is a widespread sink-based measure of soil bioavailable phosphorus (P) used in biogeochemistry and soil fertility. However, acid elution of P may hydrolyze organic P and thus compromise measurement of PO4-P. We evaluated sodium bicarbonate (NaHCO3) as an alternative to sulfuric acid (H2SO4) for PO4-P elution. We found 0.5 M NaHCO3 achieved ≈100% PO4-P recovery at higher initial PO4-P concentrations (20 and 30 mg P/L), compared to 95%–98% with 0.25 M H2SO4. For 24 soil samples representing all 12 USDA soil orders, NaHCO3 elution yielded 9.6% higher resin extractable PO4-P than H2SO4. Additionally, the PO4-P remaining in water extract after resin removal (H2Ore-PO4) was consistently quantifiable, and constituted up to 46% of total extractable PO4-P. These results demonstrate (i) NaHCO3 is a more effective eluent for resin extractable P than H2SO4, and (ii) H2Ore-PO4 should be quantified when measuring resin extractable P.

AB - Resin-extractable phosphate (PO4-P) is a widespread sink-based measure of soil bioavailable phosphorus (P) used in biogeochemistry and soil fertility. However, acid elution of P may hydrolyze organic P and thus compromise measurement of PO4-P. We evaluated sodium bicarbonate (NaHCO3) as an alternative to sulfuric acid (H2SO4) for PO4-P elution. We found 0.5 M NaHCO3 achieved ≈100% PO4-P recovery at higher initial PO4-P concentrations (20 and 30 mg P/L), compared to 95%–98% with 0.25 M H2SO4. For 24 soil samples representing all 12 USDA soil orders, NaHCO3 elution yielded 9.6% higher resin extractable PO4-P than H2SO4. Additionally, the PO4-P remaining in water extract after resin removal (H2Ore-PO4) was consistently quantifiable, and constituted up to 46% of total extractable PO4-P. These results demonstrate (i) NaHCO3 is a more effective eluent for resin extractable P than H2SO4, and (ii) H2Ore-PO4 should be quantified when measuring resin extractable P.

UR - http://www.scopus.com/inward/record.url?scp=85217367231&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85217367231&partnerID=8YFLogxK

U2 - 10.1002/ael2.70012

DO - 10.1002/ael2.70012

M3 - Article

AN - SCOPUS:85217367231

SN - 2471-9625

VL - 10

JO - Agricultural and Environmental Letters

JF - Agricultural and Environmental Letters

IS - 1

M1 - e70012

ER -

Phosphate elution from anion-exchange membranes in soil analysis

Abstract

ASJC Scopus subject areas

Online availability

Library availability

Related links

Fingerprint

Cite this