HORIZONTAL Factsheet
AOX
version: 2/15/2016
SUBJECT
Determination of AOX
HORIZONTAL number
10
Matrices
Soil and sludge
Existing standards used as basis
Work package
DIN 39 414 – S 18
CEN/TC 292, CEN/TC 308, CEN/TC 345, ISO/TC
190
5 Organic parameters
Project
STREP FP6 HORIZONTAL-ORG
Expert
Ulla Lund
Organisation
Eurofins A/S
Country
Denmark
Email
Status
uol@eurofins.dk
Standardisation Committees
Desk study First
Comments Phase I
Final version
Phase II Ruggedness
August 2003
October 2003
December 2003
Ongoing work
www.ecn.nl/horizontal
Completion due 31-03-05
Second consultation
Completion due 30-05-05
Validation
Completion due 31-12-05
Transfer to BT/TF151
Foreseen 31-03-06
Summary of AOX procedure
The AOX-procedure describes an empirical method for determination of organically bound
chlorine, bromine and iodine adsorbed and occluded in the sample matrix. It is intended for
analysis of solid material, such as sludge or soil. The intended concentration range is from 5
mg/kg dry matter to 6 g/kg dry matter.
The principle of the method is:
 Addition of activated carbon to the dried, homogenised solid sample.
 Elution of inorganic halides and simultaneous adsorption of water soluble organic
compounds on the activated carbon by shaking with acidified nitrate solution.
 Combustion of the sample/loaded activated carbon mixture at > 950ºC in an oxygen
stream.
 Absorption of the hydrogen halides produced followed by determination of the halide
ions by argentometric titration, such as microcoulometry.
HORIZONTAL Factsheet
AOX
version: 2/15/2016
Placement of AOX method in overall structure HORIZONTAL
SLUDGE, SOIL, TREATED BIOWASTE AND RELATED
WASTES
SAMPLING
IN-SITU ,TRANSPORT, STORAGE
SAMPLE PRETREATMENT - INORG
INORGANIC
CONSTITUENTS
PHYSICAL
PROPERTIES
SAMPLE PRETREATMENT
- HYG
SAMPLE PRETREATMENT - ORG & BIOL
LEACHING
ORGANIC
PARAMETERS
BIOLOGICAL
PARAMETERS
HYGIENIC
PARAMETERS
PAH
pH
Bulk density
Characterisation
leaching tests
Impurities (e.g
glass, plastic)
E. Coli
Stability (bio)
Salmonella
Germinating
weed seeds
Clostridium
Phytotoxicity
Enterococci
AOX
Electrical
conductivity
Dry matter
Compliance
leaching tests
PCB
Organic matter*
Solidity
LAS, NP,NPE
Nutrients N, P,
K*
Thixotropic
behaviour
DEPH, DBP
Trace elements
solid *
Trace elements
determination*
Piling
behaviour
Helminth ova
BFR
Flowability
Rapid methods
PCCD/PCDF
Soluble P
Virusses and
bacteriophages
Pharmaceuticals
Plant
Pathogens
Position of AOX method in the sequence of steps from sampling to reporting
Sampling Taking of
plan
sample
Transport & Preparation
storage
of test
portion
(x)
Extraction/
Leaching
Pre-treatment
x
Detection &
Summary
Quantification, reports
Enumeration
x
x
1)Sample conservation, storage and transport are issues that generally are covered in as the final step in sampling standards
2) Preparation of the test portion from a laboratory sample is sometimes part of the next step (digestion or analysis preparation) or can
be covered in a separate standard
3) Summary of test results is a concise summary of the relevant data for the end-user, which can be merged in an overall test report
covering all aspects relevant for the given situation.
4) After defining sampling strategy based on the question to be answered either one of the sampling standards will generally apply. All
the following steps will be the same for either route.
5) It is at present not clear where extraction of organic parameters begins and pre-treatment ends. It seems that pre-treatment now includes
the extraction step.
Major issues of discussion
 Can soil be covered by the standard?
 Will a low carbon to sample ratio lead to incomplete combustion?
 Is inorganic chloride effectively removed during sample pre-treatment?