08/1491 - MCU - Detached House [As Published] · 132008.1491

of relatively Insoluble sulfate salts (such as jarosite, natrojarosite, and other iron and aluminium hydroxy-sulfate minerals).

SCR: The symbol givan to the result from the Chromium Reducible Sulfur method (Method 22B). The SCR method providas a measure of reduced inorganic
sulfide content using iodometric titration after an acidic chromous chloride reduction. This method is not subject to interferences from organic sulfur.

SHCI: Sulfur soluble in 4 M HCI which includes soluble and adsorbed sulfate, sulfate from gypsum, as well as sulfate from hydroxy-sulfate minerals such as
jarosite and natrojarosite.

SKCI: Potassium chloride extractable sulfur measured fottowing the T AA analysis, which includes soluble and adsorbed sulfate as well as sulfate from gypsum.

SNAS: Net acid soluble sulfur. (SHC! -SKCI. The sulfur soluble in 4 M HC! that is not soluble in 1 M KCI. It provides an estimate of the suifate contained in
jarosite and similar low solubility hydroxy-sulfate minerals (and can be used to estimate retained acidity).

Sp: Peroxide sulfur, Sulfur measured following the TPA analysis, which Inciudes soluble and exchangeable sulfate, sulfate from gypsum, as well as sulfide
converted to sulfate and that released from organic matter as a result of peroxide oxidation.

SP Os: Peroxide oxidisable sulfur from the SPOCAS method. The sulfur soluble after the peroxide digest and TPA titration that was not solubie following KC1-
extraction and TAA titration, (Sp -SKCL. It provides an estimate of the soll sulfide content, but Is affected by the prasence of organic sulfur.

SRAS: Residual acid soluble sulfur. The sulfur measured by 4 M HCI extraction on the soil residue remaining after peroxide digestion and TP A titration
Q SPOCAS method. It provides an estimate of the sulfate contained In jarosite and similar tow solubility hydroxy-sulfate minerals (and can be used
stimate retained acidity).

ST: Total sulfur. A measure of the total sulfur content of the soll, encompassing both organic and inorganic forms,

Sros: Total oxidisable sutfur. An estimate of soll oxtdisable sulfur made from determining the sulfur not soluble in 4 MHCt. (ST -SHCI). It tands to provide

an overestimate of soil sulfide content.

Self-neutrallsing soils: This term is given to ASS where there is sufficient acid neutralising capacity (with the relevant safety factor applied) to neutralise
the potential sulfidic acidity held In the soil (je. the net acidity from the Acid Base Account Is zero or negative). Soils may be 'self- neutralising’ due to
an abundance of naturally occurring calclum or magnesium carbonates (ag. crushed shalls, marine animal exoskeletons, coral) or other acid-neutralising

material.

SPOCAS: An acronym standing for Suspension Peroxide Oxidation Combined Acidity and Sulfur method (Method Code 23), the peroxide-basad method
that supersedes the previous POCAS and POCASm methods,

SPOCAS Sulte: The acid base accounting approached used to calculate net acidity based on the Suspension Peroxide Oxidation Combined Acidity
and Sulfur method. A dacision tree approach based on the values of pHKCI and pHox is used to decide what analytical path Is followed In order to allow

on" of net acidity.

TAA: Titratable actual acidity. The acidity measured by titration with dilute NaOH following extraction with KCi-solution in the SPOCAS method.
Previously referred to as Total Actual Acidity in the POCAS and POCASm methods.

TPA: Titratable peroxide acidity. The acidity measured by titration with dilute NaOH following peroxide digestion in the SPOCAS method. Previously
referred to as Total Potential Acidity in the POCAS and POCASm methods.

TSA: Titratable sulfidic acidity. The difference in acidity measured by titration with dilute NaOH following extraction with KCl-solution and the acidity

titrated following peroxide digestion in the SPOCAS method. (TPA -TAA). Previously referred to as Total Sulfidic Acidity in the POCAS and POCASm
methods.

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