LC‐ICP‐MS analysis of inositol phosphate isomers in soil offers improved sensitivity and fine‐scale mapping of inositol phosphate distribution

• Published in: Methods in ecology and evolution Vol. 15; no. 3; pp. 530 - 543
• Main Authors: Carroll, Joseph J., Sprigg, Colleen, Chilvers, Graham, Delso, Ignacio, Barker, Megan, Cox, Filipa, Johnson, David, Brearley, Charles A.
• Format: Journal Article
• Language: English
• Published: London John Wiley & Sons, Inc 01.03.2024; Wiley
• Subjects: Biogeochemical cycles; Boreal forests; Edetic acid; Ethylenediaminetetraacetic acids; Fertilization; Forest soils; Inductively coupled plasma; Inositol phosphate; inositol phosphate isomers; Inositol phosphates; Inositols; Isomers; LC‐ICP‐MS; Liquid chromatography; Magnetic resonance spectroscopy; Mass spectrometry; Mass spectroscopy; nitrogen fertilization; NMR; NMR spectroscopy; Nuclear magnetic resonance; Organic phosphorus; phosphorus speciation; phytate; Sodium hydroxide; soil 31P NMR; Soil improvement; Soils; Speciation
• ISSN: 2041-210X; 2041-210X
• DOI: 10.1111/2041-210X.14292

Organic forms of phosphorus (P) prevail in soils and their quantification is vital to better understand global biogeochemical cycles. P speciation in soil is commonly assessed by 31P NMR spectroscopy of sodium hydroxide‐EDTA (NaOH‐EDTA) extracts. A liquid chromatography‐inductively coupled plasma‐mass spectrometry (LC‐ICP‐MS) method that employs NaOH‐EDTA is described. Comparison with 31P NMR shows that LC‐ICP‐MS is up to three orders of magnitude more sensitive. It allows measurement in samples as small as 1 mg. We reveal variation of inositol phosphate distribution in Swedish boreal forest soil and identify myo‐ and scyllo‐inositol hexakisphosphates and other isomers including scyllo‐inositol pentakisphosphate. Speciation of the major inositol phosphates was not altered by long‐term nitrogen fertilization.