In:
Rapid Communications in Mass Spectrometry, Wiley, Vol. 36, No. 22 ( 2022-11-30)
Abstract:
Phosphate (PO 4 ) oxygen isotope (δ 18 O PO4 ) analysis is increasingly applied to elucidate phosphorus cycling. Due to its usefulness, analytical methods continue to be developed and improved to increase processing efficiency and applicability to various sample types. A new pretreatment procedure to obtain clean Ag 3 PO 4 using solid‐phase extraction (SPE) with zirconium‐loaded resin (ZrME), which can selectively adsorb PO 4 , is presented and evaluated here. Methods Our method comprises (1) PO 4 concentration, (2) PO 4 separation by SPE, (3) cation removal, (4) Cl − removal, and (5) formation of Ag 3 PO 4 . The method was tested by comparing the resulting δ 18 O PO4 of KH 2 PO 4 reagent, soil extracts (NaHCO 3 , NaOH, and HCl), freshwater, and seawater with data obtained using a conventional pretreatment method. Results PO 4 recovery of our method ranged from 79.2% to 97.8% for KH 2 PO 4 , soil extracts, and freshwater. Although the recovery rate indicated incomplete desorption of PO 4 from the ZrME columns, our method produced high‐purity Ag 3 PO 4 and accurate δ 18 O PO4 values (i.e., consistent with those obtained using conventional pretreatment methods). However, for seawater, the PO 4 recovery was low (1.1%), probably due to the high concentrations of F − and SO 4 2− which interfere with PO 4 adsorption on the columns. Experiments indicate that the ZrME columns could be regenerated and used repeatedly at least three times. Conclusions We demonstrated the utility of ZrME for purification of PO 4 from freshwater and soil extracts for δ 18 O PO4 analysis. Multiple samples could be processed in three days using this method, increasing sample throughput and potentially facilitating more widespread use of δ 18 O PO4 analysis to deepen our understanding of phosphorus cycling in natural environments.
Type of Medium:
Online Resource
ISSN:
0951-4198
,
1097-0231
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
2002158-6
detail.hit.zdb_id:
58731-X
SSG:
11
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