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AS 4969.12-2009
$125.14
Analysis of acid sulfate soil — Dried samples — Methods of test, Method 12: Complete suspension peroxide oxidation combined acidity and sulfur (SPOCAS) method
This Standard specifies a method for the determination of pH in a 1 M KCl soil suspension, and, where required, titratable actual acidity (TAA) in acid sulfate soil. Following this, potassium chloride extractable sulfur (SKCl), calcium (CaKCl) and magnesium (MgKCl) are determined.
Table of contents
Header
About this publication
Preface
1 SCOPE
2 REFERENCED DOCUMENTS
3 DEFINITIONS
4 PRINCIPLE
5 REAGENTS
5.1 General
5.2 Calibration solutions for the pH meter
5.2.1 General
5.2.2 Buffer solution, pH 4.00 at 20°C
5.2.3 Buffer solution, pH 6.88 at 20°C
5.2.4 Buffer solution, pH 9.22 at 20°C
5.3 Copper chloride solution, 400 mg Cu/L as CuCl2.2H2O
5.4 Hydrochloric acid, ρ20 1.16 g/mL (HCl)
5.5 Hydrochloric acid solution, 0.5 M (Standardized)
5.6 Hydrochloric acid solution 4 M
5.7 Hydrogen peroxide, 30% (w/w) H2O2 (bulk peroxide for digestion)
5.7.1 Checking acidity of hydrogen peroxide
5.7.2 Checking sulfur content of hydrogen peroxide
5.8 Hydrogen peroxide H2O2 30% (w/w) (pH adjusted)
5.9 Potassium chloride solution, 1 M
5.10 Potassium chloride solution, 2.66 M
5.11 Standardized sodium hydroxide (NaOH) solutions
5.11.1 0.25 M NaOH
5.11.2 0.05 M NaOH
6 APPARATUS
6.1 General
6.2 Automatic titration instrument or pH meter
6.3 Beaker or other container
6.4 Burette
6.5 Centrifuge
6.6 Dispenser (manual or automatic)
6.7 Dispenser (manual or automatic)
6.8 Electronic balance 1
6.9 Electronic balance 2
6.10 Filter paper
6.11 Funnel
6.12 Glass beaker borosilicate (Digestion beaker)
6.13 pH electrodes
6.14 Pipettes
6.15 Sample bottle
6.16 Shaking or mixing machine
6.17 Steambath, or electric hotplate
6.18 Stirrer
6.19 Temperature sensor
6.20 Titration vessel
6.21 Wash bottle with narrow aperture
7 PROCEDURE FOR DETERMINATION OF pHKCl AND TAA
7.1 Preparation of the suspension
7.2 Measurement of pHKCl
7.2.1 Calibration of automatic titrator, or pH meter
7.2.2 Measurement of pH
7.3 Measurement of TAA
7.3.1 General
7.3.2 Procedure based on pHKCl result
8 TAA CALCULATIONS
9 PROCEDURE FOR DETERMINATION OF 1 M KCl EXTRACTABLE SULFUR (SKCl) CALCIUM (CaKCl) AND MAGNESIUM (MgKCl)
10 CALCULATION OF SKCl, CaKCl AND MgKCl
11 PROCEDURE FOR DETERMINATION OF PEROXIDE pH (pHOX), TITRATABLE PEROXIDE ACIDITY (TPA) AND EXCESS ACID NEUTRALIZING CAPACITY (ANCE)
11.1 Peroxide digestion of sample
11.2 Measurement of pHOX
11.2.1 Calibration of automatic titrator, or pH meter
11.2.2 Measurement of pH
11.2.3 Procedures based on pHOX result
11.3 Carbonate modification (HCl titration to pH 4)
11.4 Decomposition of excess peroxide
11.5 Measurement of titratable peroxide acidity (TPA)
11.5.1 General
11.5.2 Procedure
12 CALCULATION OF TPA AND ANCE
12.1 Notation
12.2 TPA without carbonate modification
12.3 ANCE (or TPA) with carbonate modification
12.3.1 Calculation of acidity from HCl titration
12.3.2 Calculation of excess acid neutralizing capacity in acidity units
13 PROCEDURE FOR DETERMINING PEROXIDE SULFUR (SP), CALCIUM (CaP) AND MAGNESIUM (MgP)
14 CALCULATION OF PEROXIDE SULFUR (SP), CALCIUM (CaP) AND MAGNESIUM (MgP)
15 PROCEDURE FOR DETERMINING ACID EXTRACTABLE SULFUR IN SOIL RESIDUE AFTER PEROXIDE OXIDATION (SRAS)
15.1 General
15.2 Rinsing of peroxide digested soil residue, extraction with 4 M HCl and determination of extractable sulfur
16 CALCULATION OF SRAS
16.1 Calculation of SRAS
16.2 Calculation of acidity attributed to SRAS (acid base accounting)
17 CALCULATION OF TSA
18 CALCULATION OF SPOS, CaA and MgA
19 PRECISION
19.1 General
19.2 Notation for Table 1
20 TEST REPORT
APPENDIX A
Cited references in this standard
Content history
AS 4969.12-2009 REC:2018
DR 07218
Please select a variation to view its description.
| Published | 18/03/2009 |
|---|---|
| Pages | 21 |
Please select a variation to view its pdf.
