ISO 14388-3:2014 PDF

Scope: This part of ISO 14388 specifies a suite of methods used to determine net acidity in acid sulfate soils. This part of ISO 14388 specifies a method for the determination of pH in a 1 mol/l potassium chloride soil suspension (pHKCl) and where required, titratable actual acidity (TAA). Following this, potassium chloride extractable sulfur (SKCl), calcium (CaKCl) and magnesium (MgKCl) are determined. On a separate test portion, following digestion with 30 % hydrogen peroxide, peroxide pH (pHOX ), titratable peroxide acidity (TPA) and excess acid neutralizing capacity (ANCE) are determined. Following this, peroxide sulfur (SP), calcium (CaP) and magnesium (MgP) are determined. On samples where jarosite is present, or where pHKCl is < 4,5, residual acid soluble sulfur (SRAS) is determined on the soil residue remaining after peroxide digestion. Titratable sulfidic acidity (TSA), reacted calcium (Ca A), reacted magnesium (Mg A) and peroxide oxidizable sulfur (SPOS) are then determined by difference. For peat samples containing substantial levels of organic sulfur, the SPOCAS suite is generally unsuitable for estimating sulfide content, and the chromium reducible suite of procedures should be used instead.

ISO 14388-3:2014 Referenced Document

ISO 1042:1998 Laboratory glassware - One-mark volumetric flasks
ISO 14254:2001 Soil quality - Determination of exchangeable acidity in barium chloride extracts
ISO 14388-1:2014 Soil quality - Acid-base accounting procedure for acid sulfate soils - Part 1: Introduction and definitions, symbols and acronyms, sampling and sample preparation
ISO 1770:1981 Solid-stem general purpose thermometers
ISO 3696:1987 Water for analytical laboratory use; Specification and test methods
ISO 648:2008 Laboratory glassware - Single-volume pipettes
ISO 835:2007 Laboratory glassware - Graduated pipettes
ISO 8655-1:2002 Piston-operated volumetric apparatus - Part 1: Terminology, general requirements and user recommendations
ISO 8655-2:2002 Piston-operated volumetric apparatus - Part 2: Piston pipettes
ISO 8655-3:2002 Piston-operated volumetric apparatus - Part 3: Piston burettes
ISO 8655-5:2002 Piston-operated volumetric apparatus - Part 5: Dispensers

2014 ISO 14388-3:2014 Soil quality - Acid-base accounting procedure for acid sulfate soils - Part 3: Suspension peroxide oxidation combined acidity and sulfur (SPOCAS) methodology