Abstract
Recently a dilute nitric acid extraction (0.43 M) was adopted by ISO (ISO-17586:2016) as standard for extraction of geochemically reactive elements in soil and soil like materials. Here we evaluate the performance of this extraction for a wide range of elements by mechanistic geochemical modeling. Model predictions indicate that the extraction recovers the reactive concentration quantitatively (>90%). However, at low ratios of element to reactive surfaces the extraction underestimates reactive Cu, Cr, As, and Mo, that is, elements with a particularly high affinity for organic matter or oxides. The 0.43 M HNO3 together with more dilute and concentrated acid extractions were evaluated by comparing model-predicted and measured dissolved concentrations in CaCl2 soil extracts, using the different extractions as alternative model-input. Mean errors of the predictions based on 0.43 M HNO3 are generally within a factor three, while Mo is underestimated and Co, Ni and Zn in soils with pH > 6 are overestimated, for which possible causes are discussed. Model predictions using 0.43 M HNO3 are superior to those using 0.1 M HNO3 or Aqua Regia that under- and overestimate the reactive element contents, respectively. Low concentrations of oxyanions in our data set and structural underestimation of their reactive concentrations warrant further investigation.
| Original language | English |
|---|---|
| Pages (from-to) | 2246-2253 |
| Journal | Environmental Science and Technology |
| Volume | 51 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 21 Feb 2017 |
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Evaluation of the Single Dilute (0.43 M) Nitric Acid Extraction to Determine Geochemically Reactive Elements in Soil. / Groenenberg, Jan E.; Römkens, Paul F.A.M.; van Zomeren, André; Rodrigues, S.M.; Comans, Rob N.J.
In: Environmental Science and Technology, Vol. 51, No. 4, 21.02.2017, p. 2246-2253.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Evaluation of the Single Dilute (0.43 M) Nitric Acid Extraction to Determine Geochemically Reactive Elements in Soil
AU - Groenenberg, Jan E.
AU - Römkens, Paul F.A.M.
AU - van Zomeren, André
AU - Rodrigues, S.M.
AU - Comans, Rob N.J.
PY - 2017/2/21
Y1 - 2017/2/21
N2 - Recently a dilute nitric acid extraction (0.43 M) was adopted by ISO (ISO-17586:2016) as standard for extraction of geochemically reactive elements in soil and soil like materials. Here we evaluate the performance of this extraction for a wide range of elements by mechanistic geochemical modeling. Model predictions indicate that the extraction recovers the reactive concentration quantitatively (>90%). However, at low ratios of element to reactive surfaces the extraction underestimates reactive Cu, Cr, As, and Mo, that is, elements with a particularly high affinity for organic matter or oxides. The 0.43 M HNO3 together with more dilute and concentrated acid extractions were evaluated by comparing model-predicted and measured dissolved concentrations in CaCl2 soil extracts, using the different extractions as alternative model-input. Mean errors of the predictions based on 0.43 M HNO3 are generally within a factor three, while Mo is underestimated and Co, Ni and Zn in soils with pH > 6 are overestimated, for which possible causes are discussed. Model predictions using 0.43 M HNO3 are superior to those using 0.1 M HNO3 or Aqua Regia that under- and overestimate the reactive element contents, respectively. Low concentrations of oxyanions in our data set and structural underestimation of their reactive concentrations warrant further investigation.
AB - Recently a dilute nitric acid extraction (0.43 M) was adopted by ISO (ISO-17586:2016) as standard for extraction of geochemically reactive elements in soil and soil like materials. Here we evaluate the performance of this extraction for a wide range of elements by mechanistic geochemical modeling. Model predictions indicate that the extraction recovers the reactive concentration quantitatively (>90%). However, at low ratios of element to reactive surfaces the extraction underestimates reactive Cu, Cr, As, and Mo, that is, elements with a particularly high affinity for organic matter or oxides. The 0.43 M HNO3 together with more dilute and concentrated acid extractions were evaluated by comparing model-predicted and measured dissolved concentrations in CaCl2 soil extracts, using the different extractions as alternative model-input. Mean errors of the predictions based on 0.43 M HNO3 are generally within a factor three, while Mo is underestimated and Co, Ni and Zn in soils with pH > 6 are overestimated, for which possible causes are discussed. Model predictions using 0.43 M HNO3 are superior to those using 0.1 M HNO3 or Aqua Regia that under- and overestimate the reactive element contents, respectively. Low concentrations of oxyanions in our data set and structural underestimation of their reactive concentrations warrant further investigation.
U2 - 10.1021/acs.est.6b05151
DO - 10.1021/acs.est.6b05151
M3 - Article
VL - 51
SP - 2246
EP - 2253
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 4
ER -